You've heard Andarine S4 can strip fat while preserving muscle—but what's the catch? Most people jump into SARMs without understanding how they actually work. That's like driving a sports car without knowing how to shift gears.

We're breaking down exactly what Andarine does in your body, from its cutting power to potential vision changes. Here's what you'll discover:

• What Andarine S4 is and how it targets muscle tissue

• The science behind its fat-burning and muscle-preserving effects

• Research applications and why scientists choose S4

• Real side effects you need to know about

• Chemical interactions and health warnings

• Where to buy legitimate Andarine

At Sarms UP, we've seen thousands of users get results with our 99% pure, third-party tested Andarine S4. Our pharmacologists ensure every batch meets pharmaceutical standards—because quality matters when you're serious about cutting.

What Is Andarine S4?

Andarine S4 is a selective androgen receptor modulator (SARM) that was originally developed by GTx Inc. for treating muscle wasting and osteoporosis. Consider it as a precision tool that targets specific tissues instead of flooding your entire system like traditional steroids.

Here's what makes S4 different:

• Selective binding - Attaches to androgen receptors in muscle and bone tissue

• Partial agonist - Activates receptors without full androgenic effects

• High bioavailability - Your body actually absorbs and uses it efficiently

• Research code S-4 - Also known as GTx-007 in clinical studies

The molecular structure of Andarine allows it to bind with high affinity to androgen receptors. Once attached, it triggers anabolic activity in muscle tissue while minimizing effects on other organs. This selectivity is why researchers got excited—you get muscle benefits without the typical steroid baggage.

Unlike testosterone that hits receptors everywhere, S4 shows tissue-selective activity. Studies demonstrate it has about ⅓ the androgenic activity of testosterone propionate in prostate tissue, but maintains strong anabolic effects in muscle. That's the sweet spot researchers were hunting for.

What Does Andarine S4 Do?

Andarine pulls off a metabolic magic trick—it burns fat while keeping your hard-earned muscle intact. Most cutting compounds force you to pick one or the other. Not S4.

The fat-burning effects happen through multiple pathways:

• Increases lipolysis - Your body breaks down stored fat faster

• Improves insulin sensitivity - Better nutrient partitioning means less fat storage

• Boosts metabolic rate - You burn more calories even at rest

• Reduces lipogenesis - Your body creates less new fat tissue

Research shows S4 can reduce body fat by up to 8% in 12 weeks while subjects maintained or even gained lean mass. That's not just water weight—we're talking actual fat loss you can see and measure.

How Does Andarine Work?

S4's muscle-preserving power comes from its anabolic signaling in skeletal muscle. When you're in a caloric deficit, your body wants to burn everything for fuel—including muscle. Andarine changes the game by:

• Activating protein synthesis pathways even during cuts. Your muscles keep building and repairing despite lower calories. Studies show S4 increases muscle mass by 1-2kg while subjects simultaneously lost fat.

• Preventing catabolism through androgen receptor activation. This blocks muscle breakdown signals that normally fire during dieting. You maintain strength and fullness instead of going flat.

• Enhancing muscle hardness through improved nitrogen retention. Users report a dry, vascular look within 2-3 weeks. That's why bodybuilders love S4 during contest prep—it creates that grainy, striated appearance judges want to see.

The best part? These effects kick in at just 25-50mg daily. Our customers using Sarms UP Andarine S4 consistently report maintaining bench press and squat numbers throughout aggressive cuts.

Andarine S4 for Research

Scientists gravitate toward S4 because it delivers measurable, reproducible results in controlled settings. Unlike many research compounds that show promise in theory but fail in practice, Andarine has demonstrated consistent effects across multiple studies.

Early clinical trials focused on treating muscle wasting conditions. Researchers discovered S4 could increase lean muscle mass by 3.3kg over 12 weeks—without the prostate enlargement seen with anabolic steroids. This selectivity made it a prime candidate for further investigation.

Current research applications include:

• Osteoporosis treatment - S4 significantly improves bone mineral density

• Cachexia management - Prevents muscle loss in cancer patients

• Age-related sarcopenia - Helps elderly subjects maintain lean body mass

• Post-surgery recovery - Accelerates healing and preserves muscle tissue

Why Perform Research with Andarine S4 As A Choice Of SARM

Researchers choose S4 over other SARMs for its predictable pharmacokinetics. With a 4-hour half-life, it clears quickly enough to study acute effects while maintaining stable blood levels with twice-daily dosing.

The compound offers several research advantages:

• Clean data collection - S4 doesn't interfere with natural testosterone production as severely as traditional hormone replacement therapy. This allows researchers to isolate its direct effects without confounding variables.

• Safety profile - Human clinical trials showed minimal adverse effects at therapeutic doses. No significant impact on liver enzymes, lipids, or prostate weight compared to control groups.

• Tissue selectivity - Scientists can study anabolic effects in muscle while monitoring for unwanted androgenic activity. This helps advance our understanding of selective receptor modulation.

• Dose-response relationship - Effects scale predictably from 25-75mg, giving researchers precise control over outcomes.

Important note: While extensively studied, S4 isn't approved for human consumption by regulatory bodies. The dietary supplement industry cannot legally market it, and the World Anti Doping Agency bans its use in competitive sports.

Sarms UP provides research-grade Andarine specifically for laboratory and research purposes only. Our pharmaceutical-grade purity ensures your research data isn't compromised by contaminants or dosing inconsistencies.

Andarine S4 Side Effects

The most common issue users report is vision disturbances, specifically a yellow tint and difficulty adjusting between light and dark environments. This happens because S4 binds to receptors in your eyes.

Here's what research on intact animals and human trials revealed:

• Vision changes (50% of users at 50mg+) - Yellow tinting, night blindness

• Mild testosterone suppression - 20-30% reduction in endogenous testosterone

• Dry joints - Some users report decreased joint lubrication

• Mood changes - Irritability or aggression in sensitive individuals

The good news? These effects are dose-dependent and reversible. Studies on male rats showed complete recovery within 4 weeks of discontinuation. No permanent damage to androgenic organs or liver injury was observed at therapeutic doses.

Research data from castrated male rats demonstrated S4's impact on body composition without affecting total body weight—suggesting water retention isn't an issue. This investigational drug showed high binding affinity to muscle tissue while sparing the prostate.

Andarine Precautions And Warnings

Before fitness enthusiasts consider S4, understand these critical factors:

• Testosterone suppression is real. While milder than steroids, you'll still experience some shutdown. Blood work shows LH and FSH drop by week 4, though not as severely as with traditional anabolics.

• Vision sides aren't random. The chemical structure of S4 means it will bind to ocular receptors at higher doses. Start low (25mg) and assess your tolerance before increasing.

• Not for long-term use. Research protocols typically run 8-12 weeks. Extended use increases the risk of suppression and may impact growth factor production.

Who should avoid S4 completely:

• Anyone under 21 (bone mass still developing)

• Those with existing eye conditions

• People on medications that affect vision

• Anyone with liver or kidney issues

For body recomposition goals, many users stack S4 with other SARMs. However, this increases the likelihood of suppression and compounds potential risks. Single-compound cycles let you identify what's causing any issues.

Where To Buy Andarine for Lean Muscle Mass

Finding legitimate S4 is trickier than you'd think. The market's flooded with underdosed products and questionable suppliers claiming 99% purity without proof.

Here's what separates real Andarine from expensive fakes:

• Third-party testing certificates - Not just claims, actual lab reports

• Consistent 25mg dosing - Many brands sell 10-15mg caps labeled as 25mg

• Pharmaceutical-grade facilities - Proper manufacturing prevents contamination

• Batch tracking - Every bottle traceable to its test results

Sarms UP Andarine S4

Our standalone Andarine S4 delivers exactly what researchers need—pure, accurately dosed S4 at $79.99 (down from $99.99). With 56 verified reviews averaging 4.8 stars, it's our most trusted cutting compound.

What you're getting:

• 25mg pharmaceutical-grade S4 per capsule

• Enhanced fat loss while preserving muscle

• Improved recovery between training sessions

• Joint healing properties many users don't expect

• Safe for both male and female researchers

Each bottle undergoes HPLC testing to verify purity and potency. We reject any batch below 99% purity—period.

Lean Mass Stack

For advanced body recomposition, our Lean Mass Stack combines S4's cutting power with LGD-4033 and RAD-140 for $359.99 (20% off regular price). This isn't random—these compounds work synergistically.

The stack includes:

• 2x Andro Max LGD-4033 - Builds dense muscle tissue

• 2x Andarine S4 - Cuts fat and hardens muscle

• 1x Test Max RAD-140 - Amplifies strength gains

With 57 reviews, users report gaining 5-8lbs of lean mass while dropping body fat. That's the holy grail of body transformation.

Shred Women Stack

Women have unique needs, which is why we created the Shred Women Stack at $209.99 (save $60). This combines S4 with non-suppressive compounds for maximum fat loss without virilization concerns.

You get:

• Andarine S4 - Primary fat burner and muscle hardener

• SR9009 Stenabolic - Boosts metabolism and endurance

• Cardarine GW501516 - Enhances fat oxidation

42 reviews confirm what we've seen in testing—women achieve competition-ready conditioning without harsh side effects. Free shipping over $150 means most orders arrive within 3-5 business days.

Andarine: What Is The Legal Status

S4 exists in a legal gray area. It's not approved for human consumption by the FDA, but it's also not a controlled substance. This means you can legally purchase it for research purposes, but companies cannot market it as a dietary supplement.

If you compete in tested sports, S4 will cause a failed drug test for up to 3 weeks after last use.

Current regulations:

• USA - Legal to buy and possess for research

• Canada - Requires research license for import

• Australia - Scheduled substance, prescription required

• UK - Legal to purchase, illegal to supply for human use

Bottom line? Know your local laws and intended use. Sarms UP ships globally but buyers assume responsibility for compliance with their country's regulations.

Ready to Cut Like a Pro? Sarms UP Has Your S4

Andarine S4 offers a unique edge for cutting—preserving muscle while torching fat. But like any powerful tool, success depends on quality and proper use.

Key takeaways:

• S4 selectively targets muscle and bone tissue

• Expect 5-8% fat loss with maintained strength

• Vision changes are the main side effect to monitor

• Start at 25mg and assess tolerance

• Legal for research, banned in competitive sports

Whether you're prepping for summer or stage, legitimate S4 makes the difference. Sarms UP's pharmaceutical-grade Andarine undergoes rigorous testing because we know results depend on purity. With 500+ five-star reviews and same-day shipping, we're the trusted choice for serious researchers ready to transform their physique.

FAQs

What is the difference between Ostarine and Andarine?

Ostarine is the gentle giant—perfect for beginners and joint healing. Andarine? That's your cutting specialist.

Key differences:

• Potency: S4 hits harder for fat loss, Ostarine's milder overall

• Side effects: Andarine causes vision issues, Ostarine doesn't

• Best use: S4 for aggressive cuts, Ostarine for lean gains and recovery

• Suppression: Both suppress testosterone, but S4 slightly more

Most users pick Ostarine for first cycles and graduate to Andarine when they need serious definition.

Which SARM shrinks the prostate?

Andarine S4 actually reduces prostate weight in research studies—that's what made scientists so excited. While testosterone and steroids enlarge the prostate, S4 showed the opposite effect in clinical trials.

Studies found S4 decreased prostate size by up to 35% in animal models while still building muscle. This tissue selectivity is why researchers consider it safer than traditional androgens. No other SARM demonstrates this prostate-shrinking effect as consistently.

What is the most studied SARM?

Ostarine (MK-2866) takes the crown with the most human clinical trials completed. It's been through Phase II trials for muscle wasting and has the largest body of research data.

However, Andarine S4 comes in a close second with extensive preclinical research and several human studies. The difference? Ostarine focused on therapeutic uses while S4 research explored both medical applications and performance enhancement.

What SARMs increase IGF-1?

MK-677 (Ibutamoren) is the IGF-1 king—it can boost levels by 60-70% within weeks. But here's the thing: it's technically not a SARM. It's a growth hormone secretagogue that triggers your body's own GH production.

True SARMs like Andarine don't directly increase IGF-1. However, S4 can indirectly support growth factors through improved nitrogen retention and protein synthesis. For maximum growth factor support, many stack S4 with MK-677.

References

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC2098692/

2. https://pmc.ncbi.nlm.nih.gov/articles/PMC2039881/

3. https://www.researchgate.net/publication/246504602_Creatine_supplementation_combined_with_resistance_training_in_older_men

4. https://www.sciencedirect.com/science/article/abs/pii/S0378111923002317