Andarine (S4)

Andarine, commonly known as S4, is a selective androgen receptor modulator (SARM) that has attracted attention for its potential effects on muscle growth, fat loss, and body composition. Originally developed by GTX Pharmaceuticals, Andarine was designed to provide targeted anabolic benefits similar to anabolic steroids, but with the goal of minimizing common side effects. While it shows promise in research settings, Andarine also carries important safety considerations, including hormonal suppression and vision-related side effects. This guide provides a clear, evidence-based overview of Andarine — how it works, what studies suggest, and the risks and considerations anyone should know before exploring its use.

Key Takeaways

• S4 is a selective androgen receptor modulator (SARM) developed by GTX Pharmaceuticals.
• It was designed to mimic anabolic effects in muscle and bone while potentially reducing side effects common to steroids.
• S4 works by binding to androgen receptors, primarily in muscle and bone tissue.
• Reported benefits include increased muscle density, fat loss, and muscle preservation during calorie restriction.
• A significant concern is vision disturbance, including yellow tint, blurred vision, and night blindness.
• Andarine can suppress natural testosterone production, necessitating post-cycle therapy (PCT).
• While not approved for human use, S4 is classified as an investigational drug in many regions.
• Users should be aware of potential risks, including hormonal imbalances and liver strain, and treat it with caution.

What is Andarine?

Background and Development History

Andarine, also identified by its developmental code GTX-007, is a compound classified as a selective androgen receptor modulator (SARM). It was originally synthesized by GTX, Inc. with the primary objective of treating conditions such as muscle wasting, osteoporosis, and benign prostatic hyperplasia (BPH).

As a SARM, Andarine was designed to selectively target androgen receptors located within muscle and bone tissues. This selectivity aimed to stimulate anabolic activity, promoting muscle growth and bone density, while theoretically minimizing the androgenic side effects commonly associated with traditional anabolic steroids. The development of SARMs like Andarine emerged in the early 2000s as researchers sought alternatives to steroidal compounds that often carried significant risks, including liver toxicity and cardiovascular issues.

Despite showing promise in preclinical research for its anabolic potential, Andarine did not advance into human clinical trials. The discontinuation of its clinical development is primarily attributed to observed visual disturbances in animal studies, which were linked to the compound’s interaction with androgen receptors in the eye. This specific side effect profile ultimately halted further investigation for therapeutic applications.

Compound Name	Development Code	Class of Compound	Original Developer	Primary Research Objectives	Status of Clinical Trials
Andarine	GTX-007	SARM	GTX, Inc.	Muscle wasting, Osteoporosis, BPH	Discontinued

How Andarine Works: Mechanism of Action Explained

Andarine (S4) operates as a selective androgen receptor modulator (SARM). Its primary mechanism involves binding to androgen receptors (ARs) located in specific tissues, most notably skeletal muscle and bone. This binding action mimics some of the effects of testosterone, a naturally occurring androgen, but with a key difference: S4 exhibits tissue selectivity.

Unlike traditional anabolic steroids, which can activate androgen receptors throughout the body, leading to a wide range of side effects, S4 is designed to primarily target muscle and bone. It acts as a full agonist in muscle tissue, promoting protein synthesis and muscle growth. However, in other tissues, such as the prostate, it functions as a partial agonist. This means it stimulates ARs to a lesser degree in these areas, theoretically reducing the androgenic side effects commonly associated with anabolic compounds, like prostate enlargement.

Furthermore, research suggests that S4 may also inhibit the binding of dihydrotestosterone (DHT) to androgen receptors. DHT is a potent androgen that contributes to various androgenic effects. By potentially reducing DHT’s influence, S4 might further mitigate some of the unwanted androgenic outcomes.

Here is a breakdown of its mechanism:

• Selective Androgen Receptor Binding: S4 preferentially binds to ARs in muscle and bone.
• Anabolic Activity: It activates ARs in muscle, leading to increased protein synthesis and muscle hypertrophy.
• Partial Agonism in Other Tissues: In tissues like the prostate, S4 acts as a partial agonist, potentially reducing unwanted androgenic effects.
• Inhibition of DHT: May interfere with DHT binding to ARs, further modulating androgenic activity.

This selective action is what differentiates SARMs like Andarine from older compounds. The goal is to achieve the anabolic benefits without the systemic androgenic drawbacks.

The development of SARMs like Andarine was driven by the desire to separate the muscle-building effects of androgens from their negative impacts on other bodily systems. This targeted approach aims for therapeutic and performance benefits with a potentially improved safety margin compared to traditional steroids.

Tissue Type	Andarine (S4) Action	Typical Androgenic Action
Skeletal Muscle	Full Agonist	Anabolic effects
Bone	Full Agonist	Anabolic effects
Prostate	Partial Agonist	Hypertrophy, BPH risk
Sebaceous Glands	Minimal/None	Acne, Oily Skin

Research on S4: What Studies Show

Research into Andarine (S4) has primarily been conducted in preclinical settings, as the compound’s development for human therapeutic use was discontinued. Despite this, the available studies offer insights into its mechanism of action and potential effects.

GTx Pharmaceuticals originally developed Andarine with the intention of treating conditions such as muscle wasting, osteoporosis, and benign prostatic hyperplasia (BPH). The compound was designed to selectively target androgen receptors in muscle and bone tissue, aiming to provide anabolic benefits without the widespread androgenic side effects associated with traditional anabolic steroids. This selectivity was a key focus in its development.

Preclinical studies suggest that Andarine exhibits a high affinity for androgen receptors in skeletal muscle, potentially promoting lean muscle mass preservation, particularly during periods of caloric restriction. It was also investigated for its ability to reduce prostate size, a characteristic that differentiated it from other androgenic compounds. Unlike dihydrotestosterone (DHT), which acts as a full agonist across various tissues, Andarine was observed to act as a full agonist in muscle but only a partial agonist in the prostate. This differential activity was considered a significant aspect of its design.

However, research also highlighted significant drawbacks. A notable finding was the compound’s interaction with ocular androgen receptors, leading to reported visual disturbances in animal models. These effects, including altered night vision and a yellowish tint to vision, were a primary reason for the discontinuation of clinical trials. The binding characteristics of S4 to these receptors are a subject of ongoing discussion in the scientific community.

Here is a summary of findings from preclinical research:

• Anabolic Activity: Studies indicated Andarine’s capacity to increase lean muscle mass and bone mineral density.
• Prostate Effects: Research suggested a potential to reduce prostate size, contrasting with the enlargement often seen with other androgens.
• Visual Side Effects: Preclinical data consistently pointed to visual disturbances as a significant adverse effect.
• Hormonal Impact: Like other SARMs, Andarine has been shown to suppress natural testosterone production in animal studies.

Study Focus	Key Finding
Muscle Anabolism	Increased lean muscle mass in preclinical models.
Bone Mineral Density	Positive effects on bone density observed.
Prostate Selectivity	Demonstrated partial agonism, potentially reducing prostate size.
Ocular Receptor Binding	Linked to visual disturbances in animal studies.
Hormonal Suppression	Indicated suppression of endogenous testosterone production.

The discontinuation of Andarine’s clinical development prior to human trials underscores the importance of thoroughly evaluating safety profiles, particularly concerning unique side effects like visual impairment. Further investigation would be required to fully understand its long-term implications and therapeutic potential, if any.

While research indicates potential benefits in muscle and bone health, the observed side effects, especially those affecting vision, have limited its progression. The scientific literature available primarily stems from animal studies and in vitro experiments, making it difficult to extrapolate definitive conclusions for human application.

Potential Benefits of Andarine

Andarine (S4) is classified as a selective androgen receptor modulator (SARM) and was initially investigated for medical purposes such as muscle wasting, osteoporosis, and prostate issues. The principal benefits attributed to Andarine relate to its effects on muscle tissue, fat metabolism, and bone health. Below, each major benefit is addressed in detail.

Muscle Growth and Strength

Andarine S4 interacts selectively with androgen receptors in muscle fibers. This receptor activity can result in muscle protein synthesis, ultimately supporting muscle growth. Unlike traditional anabolic steroids, S4 generally produces less water retention. Individuals often report the following effects:

• Noticeable increases in muscle definition
• Preservation of lean muscle in calorie deficits
• Improved physical strength, with some reporting higher repetitions or loads during resistance training

A summary of muscle-related results from studies and anecdotal reports is presented below:

Benefit	Level of Evidence	User Reports (Qualitative)
Muscle preservation	Animal studies	Common
Moderate hypertrophy	Anecdotal	Mixed (less than steroids)
Strength increase	Anecdotal	Moderate

For users focused on maintaining muscle while losing fat, S4 is primarily regarded as a supportive compound, not a main driver of bulk muscle gain.

Fat Loss

S4 may aid in fat reduction by preserving muscle mass during calorie deficits. Muscle tissue requires more energy to maintain, which can support a slightly higher metabolic rate. While not a fat-burning substance directly, its effects can contribute to greater muscle retention when cutting. Benefits include:

• Enhanced muscle hardness and visible muscle separation
• Reduced tendency for water retention compared to other compounds
• Reported smoother body recomposition (simultaneous fat loss, muscle maintenance)

Bone Density

Andarine S4 was originally tested for applications involving bone diseases such as osteoporosis. SARMs like S4 are known to stimulate bone-building pathways without substantially increasing androgenic (masculinizing) effects elsewhere in the body.

Key potential benefits to bone health include:

1. Increased bone mineral density in animal studies
2. Reduced risk of bone loss during aging or calorie restriction
3. Potential for post-injury bone recovery support

A glance at S4’s benefits compared to other SARMs:

Property	Andarine (S4)	Typical SARM 1	Typical SARM 2
Muscle gain (bulk)	Moderate	High	High
Fat loss support	Moderate	Low	Moderate
Water retention	Low	High	Moderate
Bone density potential	High	Moderate	High

Overall, S4 is valued for its balance between muscle retention, fat loss assistance, and support for bone maintenance, according to preclinical research and community experience. The mild nature of its anabolic properties makes it more suited for those seeking minor to moderate improvement in body composition, rather than dramatic mass increases.

S4 Side Effects and Risks

While Andarine (S4) is designed to offer selective benefits, it is not without potential adverse effects. Users must be aware of these risks before considering its use. The lack of extensive human trials means the full spectrum of long-term consequences remains incompletely understood.

Vision Disturbances

One of the most frequently reported and distinctive side effects associated with Andarine is visual impairment. This is believed to stem from S4’s interaction with androgen receptors present in the eye.

Reported visual disturbances can include:

• Altered color perception, often described as a yellow tint to vision (xanthopsia).
• Difficulty adapting to changes in light, particularly transitioning from bright to dark environments.
• Reduced ability to see clearly in low-light conditions (night blindness).
• Occasional visual flashes or flickering.

These effects are generally dose-dependent and temporary, often resolving after the compound is discontinued or the dosage is reduced. However, their prevalence was a significant factor in the discontinuation of S4’s clinical development.

Hormonal Imbalances

Like other selective androgen receptor modulators (SARMs), Andarine can suppress the body’s natural testosterone production. While S4 is often considered less suppressive than some other SARMs, this effect can still lead to hormonal imbalances.

Potential consequences of hormonal suppression include:

• Decreased libido.
• Lethargy or fatigue.
• Mood disturbances.
• Acne.
• In some cases, testicular atrophy.

Furthermore, Andarine does not aromatize into estrogen, but the disruption of the natural hormonal balance can indirectly affect estrogen levels, potentially exacerbating some of these issues. There are also concerns regarding reductions in sex hormone-binding globulin (SHBG) and high-density lipoprotein (HDL) cholesterol, which may have implications for cardiovascular health.

Liver Toxicity Concerns

Although SARMs are often presented as having a lower risk of liver toxicity compared to traditional anabolic steroids, there remains a potential for hepatic stress. Some users may experience elevated liver enzymes, which can indicate strain or damage to the liver.

While therapeutic doses might present a lower risk profile, higher doses, often used for performance enhancement, may still carry hepatotoxic risks. It is prudent to monitor liver function when using such compounds.

The potential for S4 side effects, particularly vision disturbances and hormonal suppression, necessitates careful consideration and risk assessment. While Andarine benefits such as muscle hardening and preservation are noted, they must be weighed against these significant risks.

There is no definitive evidence linking Andarine directly to cancer, but any compound that significantly alters hormonal pathways warrants caution. The long-term effects and the full extent of risks, including potential interactions with other substances or pre-existing conditions, are not fully established due to limited human research. Users should be aware that Andarine is classified as a research chemical and is not approved for human consumption.

How to use S-4?

Andarine S4, a selective androgen receptor modulator (SARM), is typically administered orally. Due to its relatively short half-life, which is estimated to be around 4 to 6 hours, users often divide their daily dosage to maintain consistent blood levels throughout the day. This split dosing strategy is a common practice among individuals utilizing S4 for its potential effects on muscle and bone.

The recommended s4 dose can vary significantly based on individual goals and experience levels. However, a common starting point for many users is between 25 mg and 50 mg per day. More experienced users might consider dosages up to 75 mg per day, though this is often associated with a higher incidence of side effects, particularly visual disturbances. It is generally advised to begin with a lower dose and gradually increase it if tolerated, while closely monitoring for any adverse reactions. A typical cycle length for Andarine S4 ranges from 6 to 8 weeks.

Here is a general guideline for Andarine S4 dosage:

Dosage Range (mg/day)	Cycle Length (Weeks)	Primary Use Case
25-50	6-8	Muscle preservation, cutting
50-75	6-8	Enhanced cutting, recomposition

It is important to note that Andarine S4 is not approved for human consumption by regulatory bodies, and its use is primarily within research settings or by individuals seeking performance enhancement. Users should be aware of the potential risks, including visual side effects and hormonal suppression, and consider consulting with a healthcare professional before use.

Proper administration involves taking the compound with water, and consistency in timing is key to achieving stable plasma concentrations. Users should also consider implementing a post-cycle therapy (PCT) protocol after completing a cycle to help restore natural hormone production, although the necessity and specific protocols for PCT with S4 can be a subject of debate among users.

Some users report that taking GTx-007 with food can help mitigate potential stomach discomfort. The anabolic-to-androgenic ratio of it is considered favorable, contributing to lean gains without significant water retention, making it a popular choice for individuals focused on body recomposition or cutting phases.

Trends and Misconceptions

GTx-007 is frequently discussed within fitness communities, often accompanied by a number of prevailing trends and misconceptions that warrant careful examination. One significant misconception is the perception of S4 as a mild or entirely side-effect-free substance, particularly for novice users. This view can lead to underestimation of its potential impact on hormonal balance and overall health.

Several common errors are observed among individuals beginning to use GTx-007. These include initiating cycles at excessively high dosages, which amplifies the risk of adverse effects such as vision disturbances and hormonal suppression. Another frequent mistake is disregarding early signs of visual impairment, such as a yellowish tint to vision or difficulty with night vision. It is important to acknowledge these symptoms and adjust the dosage or discontinue use if they become pronounced. The unique visual side effects associated with Andarine (S4) are a notable characteristic that distinguishes it from other SARMs.

Furthermore, the necessity of a Post-Cycle Therapy (PCT) protocol is often overlooked. Even short cycles of S4 can lead to testosterone suppression, necessitating a recovery plan to restore natural hormone levels and mitigate potential negative consequences like mood changes or loss of muscle mass. The unregulated nature of the SARM market also presents a significant challenge. Many products available online may be underdosed, contain unlisted ingredients, or be entirely mislabeled. Verifying third-party testing is therefore a critical step for consumers.

Here is a summary of common beginner mistakes and recommended practices:

• Dosage Management: Begin with a low dose (e.g., 25 mg daily, split into two administrations) and gradually assess tolerance before considering increases. This approach helps mitigate the risk of adverse reactions.
• Symptom Monitoring: Pay close attention to any reported side effects, particularly visual changes. If symptoms arise, reduce the dose or cease use. Continuing use despite worsening symptoms can be detrimental.
• Post-Cycle Support: Implement a structured PCT protocol following any cycle to aid in the recovery of natural hormone production. This is considered a mandatory step for responsible use.
• Product Verification: Always seek products that have undergone independent, third-party laboratory testing to confirm their identity and purity. This helps avoid counterfeit or contaminated substances.
• Health Monitoring: Conduct baseline blood work before starting a cycle and monitor key biomarkers throughout and after use. This practice is vital for managing potential health risks and ensuring proper recovery.

The reputation of GTx-007 as a beginner-friendly compound is often a dangerous oversimplification. Its potential benefits are accompanied by distinct risks, including visual disturbances and hormonal suppression, which necessitate a cautious and informed approach. Responsible use requires diligent attention to dosage, symptom monitoring, and post-cycle recovery strategies.

Trends also include pairing GTx-007 with other compounds, such as Cardarine or MK-677, for synergistic effects, particularly during cutting phases. However, this practice further increases the complexity and potential risks involved. The market for SARMs is dynamic, with ongoing discussions about efficacy, safety, and legal status. Staying informed about the latest research and regulatory updates is important for anyone considering the use of such compounds. For those seeking performance enhancements, exploring legal alternatives may be a more prudent long-term strategy. The FDA warning letter regarding SARMs highlights the regulatory scrutiny these substances face.

GTx-007 vs. Other SARMs: Key Comparisons

When examining Andarine (S4) in the context of other Selective Androgen Receptor Modulators (SARMs), several distinctions become apparent. While all SARMs interact with androgen receptors, their specific binding affinities, tissue selectivity, and potency lead to varied outcomes and side effect profiles. Understanding these differences is key to appreciating the unique position of Andarine within this class of compounds.

Overview:

Attribute / Feature	Andarine (S4)	Ostarine (MK-2866)	Ligandrol (LGD-4033)
Typical Use / Goal	Cutting / recomposition; lean mass retention; fat loss / “dry look”	Lean mass retention / mild gains; rehab, recovery, modest recomp	Lean mass gain / muscular hypertrophy; recomposition or bulking
Relative Anabolic Strength	Moderate — more than mild SARMs, less than strong SARMs	Mild to moderate — gentler than many SARMs	High — potent for muscle gain
Fat Loss / Recomposition Potential	Good — favorable for fat loss, “hard, vascular” look	Moderate — useful for mild recomp	Moderate — more oriented toward mass gain than cutting
Common / Noted Side Effects	Vision disturbances (yellow tint, night-vision issues); mild‑moderate testosterone suppression	Mild; generally considered lower risk; some suppression possible	Higher suppression risk; possible effects on hormones, lipids, liver enzymes at high doses
Research / Data Strength	Mostly preclinical + anecdotal; limited human data	Stronger data; more human studies than S4	Preclinical + some human studies; more extensive than most SARMs

Andarine vs. Ostarine

Ostarine (MK-2866) and Andarine (S4) were both developed by GTx Pharmaceuticals, but their development paths diverged.

• Ostarine has seen more extensive preclinical research and is often considered for therapeutic applications related to muscle wasting and bone density.
• Andarine, while showing promise, was discontinued earlier in its development, possibly due to specific side effects like vision disturbances.

Anecdotally, Ostarine is often viewed as a more general-purpose SARM for muscle gain and strength, whereas Andarine is frequently associated with a “cutting” effect, providing a harder, drier muscular appearance with less water retention. However, Andarine is generally considered less suppressive of natural testosterone production compared to some other SARMs, though suppression still occurs.

Feature	Andarine (S4)	Ostarine (MK-2866)
Primary Use (Anecdotal)	Cutting, muscle hardening, definition	Bulking, strength, general muscle gain
Potency (Muscle Gain)	Moderate	Moderate to High
Water Retention	Minimal	Low to Moderate
Testosterone Suppression	Moderate	Moderate to High
Vision Effects	Possible (yellow tint, difficulty adjusting)	Generally not reported
Half-life	Short (approx. 4-6 hours)	Longer (approx. 24 hours)

Andarine vs. Other SARMs (General Comparison)

Compared to more potent SARMs like LGD-4033 (Ligandrol) or RAD-140 (Testolone), GTx-007 is typically considered less potent for sheer muscle mass accumulation. However, it is also often perceived as having a more favorable side effect profile in terms of hormonal suppression and potential liver strain, though this is highly individual.

Compounds like S23 are significantly more suppressive than GTx-007, making S23 a less common choice for individuals seeking to avoid profound endocrine disruption. The cosmetic effects of GTx-007, such as increased muscle vascularity and a “dry” look, are often highlighted as unique benefits not as pronounced with other SARMs. It is important to note that all SARMs carry risks, and their use is not approved for human consumption.

The selective nature of SARMs means they target androgen receptors in specific tissues, aiming to maximize anabolic effects in muscle and bone while minimizing androgenic effects elsewhere. However, “selectivity” does not equate to complete absence of side effects, and individual responses can vary significantly.

Key Considerations

• Potency: Andarine is not the most potent SARM for muscle growth but offers distinct aesthetic benefits.
• Side Effects: Vision disturbances are a notable concern specific to GTx-007.
• Suppression: While it causes suppression, it may be less severe than with some other SARMs.
• Half-life: Its short half-life necessitates frequent dosing for consistent effects.

When considering GTx-007 against other compounds, users often weigh the trade-offs between muscle-building potential, aesthetic outcomes, and the risk of adverse effects.

Legal Status of GTx-007 Worldwide

The legal standing of GTx-007 varies significantly across different jurisdictions, reflecting its classification as an investigational compound rather than an approved pharmaceutical or dietary supplement. In the United States, GTx-007 is not approved by the Food and Drug Administration (FDA) for human consumption. It is classified as an investigational drug, meaning its sale and distribution for human use are prohibited.

Despite this, it is often marketed online under the guise of “research chemicals,” a practice that circumvents direct prohibition but carries legal risks if intended for human application. Furthermore, the World Anti-Doping Agency (WADA) has explicitly banned GTx-007 from competitive sports, and detection methods are in place to identify its use among athletes.

Globally, the regulatory landscape is similarly restrictive. Many countries align with the U.S. stance, classifying SARMs like GTx-007 as substances not permitted for human use outside of controlled clinical trials. This means that purchasing, possessing, or distributing Andarine for personal consumption can lead to legal repercussions. The absence of FDA approval, for instance, means no health claims can be legally made about its efficacy or safety, and it cannot be marketed as a dietary supplement.

It is imperative for individuals to understand that GTx-007 is not approved for human use in any country and is subject to strict regulations.

Here is a summary of its general legal status:

• United States: Classified as an investigational drug; illegal for human consumption. Often sold as a “research chemical.”
• International Sports: Banned by WADA and other sporting bodies.
• Other Jurisdictions: Generally prohibited for human use, though specific regulations may differ.

Table: Regulatory Classification of GTx-007

Region/Body	Classification
United States (FDA)	Investigational Drug
Global Sports (WADA)	Prohibited Substance
General Market	Not approved for human consumption

Due to these legal restrictions and the lack of human clinical trials, the use of GTx-007 for performance enhancement or any other non-research purpose is undertaken at the user’s own legal and health risk.

Where to Buy S4?

Acquiring GTx-007 requires careful consideration due to its classification. It is important to note that Andarine is not approved for human consumption by regulatory bodies such as the U.S. Food and Drug Administration (FDA). Consequently, it is not available through conventional pharmaceutical channels or as a dietary supplement.

Individuals seeking to purchase S-4 typically do so from online vendors that market the compound strictly for research purposes. This distinction is critical, as selling or advertising it for human use is prohibited. When searching to buy S4 online, consumers should exercise a high degree of caution. The market for research chemicals can be inconsistent, and product quality, purity, and authenticity can vary significantly between suppliers. Due diligence is paramount to ensure the integrity of any product obtained.

When evaluating potential sources, several factors warrant attention:

• Vendor Reputation: Look for established vendors with transparent business practices and a history of providing verifiable product information.
• Product Purity and Testing: Reputable suppliers often provide third-party laboratory testing results to confirm the purity and composition of their compounds. This data is essential for assessing product quality.
• Customer Reviews and Feedback: While anecdotal, customer feedback can offer insights into a vendor’s reliability and product consistency.
• Discreet Packaging and Shipping: Given the nature of these products, discreet shipping is often a consideration for consumers.

It is also worth noting that the legal landscape surrounding performance-enhancing substances is complex and subject to change. Organizations like the World Anti-Doping Agency (WADA) have prohibited SARMs, including S-4, in competitive sports. Athletes and individuals involved in regulated sports should be aware of these prohibitions.

Table 1: Factors to Consider When Purchasing Research Chemicals

Factor	Importance
Vendor Reputation	Indicates reliability and trustworthiness.
Product Purity	Confirms the compound is as stated and free from contaminants.
Third-Party Testing	Provides objective verification of product quality.
Customer Feedback	Offers insights into user experiences and vendor service.
Discreet Shipping	Ensures privacy during delivery.

Always ensure that any purchase is made with a clear understanding of the product’s intended use and the associated legal and safety considerations. The absence of clinical trials means that long-term effects and optimal usage protocols for S-4 remain largely unestablished.

Conclusion: Is S-4 Right for You?

S-4 presents a complex profile for individuals considering its use. While preclinical research suggests potential benefits in muscle mass and strength, alongside fat loss and improved muscle definition, its development was halted before human trials. This lack of extensive human data means long-term effects and comprehensive safety remain largely unknown.

Key considerations include:

• Vision Disturbances: A unique and significant concern associated with S-4 is its potential to cause visual side effects, such as difficulty adjusting to darkness or a yellowish tint to vision. This is due to its interaction with ocular receptors.
• Hormonal Suppression: Like other SARMs, S-4 can suppress natural testosterone production, necessitating careful management and potentially post-cycle therapy (PCT) to restore hormonal balance.
• Limited Human Data: The absence of Phase I human clinical trials means that its safety and efficacy in humans are not well-established, making it a compound with considerable unknowns.

Given these factors, S-4 is not recommended for casual or uninformed use. Individuals contemplating its use should be aware of the potential risks, including hormonal disruption and vision impairment. The decision to use S4 should be made with a thorough understanding of its properties and potential consequences, ideally in consultation with a qualified healthcare professional.

Feature	Andarine (S4)	General Considerations
Muscle Growth Potential	Moderate	Varies by individual and cycle
Fat Loss Support	Moderate	Often combined with diet and exercise
Vision Side Effects	Known Risk	Unique to S4
Hormonal Suppression	Present	Common among SARMs
Human Trial Data	Limited	Preclinical research available

Final Thoughts

Andarine is a selective androgen receptor modulator (SARM) with potential benefits for muscle density and fat loss, but its use comes with serious risks. Vision disturbances, testosterone suppression, cholesterol changes, and possible liver strain make it a high-risk compound, especially outside controlled research settings.

As a research chemical not approved for human use, long-term safety data is limited, and sourcing from unverified vendors adds further uncertainty. For individuals seeking improved fitness or body composition, focusing on safe, legal, and scientifically supported alternatives is a far more prudent strategy than experimenting with it. Understanding the risks and prioritizing health should always come first.

Frequently Asked Questions

What exactly is Andarine (S4)?

It is a type of substance called a SARM, which stands for Selective Androgen Receptor Modulator. It was created to help build muscle and bone, similar to steroids, but with the hope of causing fewer unwanted effects. It’s not an approved medicine for people to use.

How does it work in the body?

S-4 works by attaching to specific spots in your muscles and bones called androgen receptors. When it connects, it tells these areas to grow and get stronger, much like testosterone does. However, it’s designed to do this more selectively, meaning it aims to affect muscles and bones more than other parts of the body.

What are the potential benefits?

People have reported that S-4 might help increase muscle mass and strength, aid in losing body fat, and potentially improve bone density. It’s often used by those looking to get a more defined and lean physique without holding onto extra water.

What are the main side effects?

One of the most talked-about side effects is vision disturbance. This can include seeing a yellow tint to vision, having trouble seeing at night, or experiencing flashes of light. Other possible issues include changes in hormone levels, like lower natural testosterone production.

Can it cause vision problems?

Yes, vision problems are a known risk with S-4. It seems to affect the androgen receptors in the eyes, which can lead to temporary issues like a yellowish tint to vision or difficulty adjusting to darkness. These effects are usually temporary and go away when use stops.

Does it affect natural testosterone levels?

Like other SARMs, S-4 can lower the body’s natural production of testosterone. This is why some people use a strategy called Post-Cycle Therapy (PCT) after using it to help bring their hormone levels back to normal.

Is it safe for long-term use?

There isn’t enough research on humans to say if S-4 is safe for long-term use. It was stopped in development partly because of the vision side effects. Using it carries risks, and it’s important to be aware of them.

How is it typically used?

S-4 is usually taken by mouth. Because it doesn’t stay in the body for a very long time, people often split their daily dose into two parts to keep the levels more steady. Typical cycles might last around 6 to 8 weeks.

What is the legal status worldwide?

S-4 is generally not approved for human consumption and is often sold as a research chemical. Its legal status can vary by country, but in many places, it is not legal to buy or use for personal purposes.

Are there any concerns about liver health with S-4?

While SARMs are often considered less harsh on the liver than anabolic steroids, there’s still a possibility of liver stress. Some users might see changes in liver enzymes, which suggests the liver is working harder. This risk might be higher with larger doses.

Can women use it?

Using S-4 is generally not recommended for women due to a lack of research and the potential risk of virilization, which means developing male characteristics. There isn’t enough information to ensure its safety for female users.

Where can one find reliable information or buy it?

Because S-4 is a research chemical, finding trustworthy sources can be difficult. Information should be sought from scientific studies and reputable research chemical suppliers who provide third-party testing results. It’s crucial to be cautious about where it is obtained.