Is S-23 the Most Powerful SARM? Results and Risks Compared

[BigArvin]

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What Is S-23​

S-23 is a nonsteroidal selective androgen receptor modulator originally developed for male contraception. Laboratories didn’t design it for bodybuilders, but bodybuilders quickly found ways to repurpose the compound for performance enhancement. This one stood out due to its aggressive binding to androgen receptors.

Unlike approved therapies, S-23 has never passed human testing for safety. It's a research chemical, which legally means it’s not intended for human use. Still, you and I know plenty of lifters run it anyway.

S-23’s Strength Compared to Other SARMs​

Compared to your average SARM like Ostarine or even heavy hitters like RAD-140 and LGD-4033, S-23 sits at the top of the food chain in terms of raw anabolic impact. It’s not just hype. Users report rapid recomposition, shredded fat, vascularity, and rock-solid muscle hardness in a short window.

Where RAD-140 provides bulk, and LGD-4033 leans more toward strength and recovery, S-23 leans heavily into that dry, grainy, competition-ready look. It’s not as forgiving as the others, but it absolutely hits harder.

How S-23 Works in the Body​

S-23’s high binding affinity means it locks onto androgen receptors more aggressively than testosterone itself in some tissues. It tells your muscles to grow and keeps your body from storing fat.

But here’s the kicker. That same strength suppresses your natural testosterone production to near-zero levels. Your body responds to the signal and shuts down the factory. That’s why, if you’re going to run S-23, you need a serious PCT plan; otherwise, you’ll crash hard post-cycle.

S-23 Results: What Users Report​

When guys run S-23, they typically notice dramatic strength increases within a week or two. You’ll feel tighter, drier, and more vascular—especially if you’re already lean. Endurance also increases, making it a top-tier choice for cutting phases or pre-contest preparation.

You do have to dose it multiple times per day due to its short half-life, but the trade-off is consistent plasma levels and quicker results. Many users report visible changes within 10 to 14 days, especially when combined with a calorie deficit and a clean diet.

Potential Risks and Side Effects of S-23​

S-23 is not a beginner’s compound.

Forget “mild suppression.” We’re talking full testosterone shutdown in most users after just a few weeks. Libido tanks, testicle shrinkage becomes real, and without a strong PCT, you’ll feel like death post-cycle.

Other reported side effects include increased aggression, acne, night sweats, and, in some cases, hair loss. Some guys get estrogenic symptoms, too, because suppression can cause hormonal imbalances downstream.

Some potential liver strain and lipid imbalance may occur at higher doses or when stacked. You’re looking at something far riskier than your average SARM cycle. And let’s be honest. Long-term effects? No one really knows. We’re the guinea pigs.

Is S-23 Legal and Safe​

S-23 is sold online as a research chemical, which keeps it in a legal gray area.
But make no mistake. WADA and most competitive organizations ban it, so don’t even think about running it if you’re getting tested.
Quality is another concern. Since it's not FDA-regulated, purity levels vary. You’re at the mercy of underground labs unless you’ve got a trusted source, and even then, batch inconsistencies happen. One bad vial can wreck your hormones for months.

Should You Use S-23? A Realistic Perspective​

If you’re brand new to SARMs, stay far away. S-23 is better suited for advanced users who already understand how their bodies react to suppression and who have access to bloodwork, a proper post-cycle therapy (PCT), and a structured cycle plan in place.

That said, for experienced lifters seeking an edge in a hard cut or final prep stage, S-23 can deliver significant results. But don’t expect it to be forgiving. You have to go in with your eyes open.

For individuals seeking a safer path, RAD-140 or LGD-4033 can provide significant gains in size and strength with fewer side effects. S-23 is for the risk-takers who want everything in the shortest time possible—and are ready to pay for it.

Frequently Asked Questions​

How strong is S-23 compared to RAD-140 or LGD-4033?

S-23 is often considered stronger in terms of muscle hardness and fat loss. RAD-140 and LGD-4033 are powerful, but they come with less suppression and slightly fewer risks.

Does S-23 require post-cycle therapy (PCT)?

Yes, absolutely. S-23 causes near-total testosterone shutdown. A full PCT with Clomid or Nolvadex is a must to recover your natural hormone levels.

What is the ideal dosage of S-23?

Most users run between 10 and 30 mg per day, split into two or three doses. Due to its short half-life, spacing out your intake is crucial for maintaining stability.