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AC-262,536: The Underground SARM You’re About to Hear A Lot More About

There’s a good chance you’ve never heard of AC-262,536 — or if you have, it probably came up in some obscure Reddit thread or whispered in a hardcore gym circle. It’s not as mainstream as RAD-140 or LGD-4033, but it’s starting to make waves in the enhanced bodybuilding world. Why? Because this lesser-known SARM may offer a surprising combo: anabolic strength with potentially lower suppression.

In this article, we’re breaking down what AC-262 actually is, how it works in the body, what the science (and bro-science) says about it, and whether it’s worth running in your next cycle. Fully humanized, no BS, and backed by actual science where it exists — and honest real-world experience where it doesn’t.

? What Is AC-262,536?

AC-262,536 is a nonsteroidal selective androgen receptor modulator (SARM) developed by Acadia Pharmaceuticals. Unlike more well-known SARMs, AC-262 was never pushed far into clinical development. It’s remained mostly in preclinical phases, which makes it a bit of a “ghost” compound in the pharma world — but that’s part of why underground biohackers and bodybuilders are intrigued by it.

It was initially developed as a therapeutic compound aimed at muscle wasting and potentially neurodegenerative conditions. While it hasn’t seen the level of formal attention that compounds like Ostarine (MK-2866) have, AC-262 caught attention for its interesting anabolic profile and a potentially lighter side-effect load.

? How It Works

Like other SARMs, AC-262,536 selectively binds to androgen receptors in skeletal muscle and bone tissue. But what makes it different is how it modulates those receptors.

In preclinical studies, AC-262 was shown to:

• Stimulate anabolic activity in muscle tissue
• Avoid binding significantly to androgen receptors in the prostate and seminal vesicles (meaning less androgenic side effects)
• Have neuroprotective potential through androgen receptor-mediated pathways in the brain

That last point is important. AC-262 may have benefits beyond the gym — like improved cognitive function, mood, or resilience against stress, although that’s still speculative based on animal data.

Binding Affinity & Selectivity

Its binding affinity is lower than that of RAD-140 or LGD-4033, but it seems to activate the receptor in a way that still drives gains without triggering as much suppression. It’s sometimes described as a “mild but clean” SARM.

? Dosage & Half-Life

Since AC-262,536 hasn’t made it to full human trials, dosages are based largely on rat studies and anecdotal reports from users. But here’s what we know:

Common Dosage Range (anecdotally):

• 10mg to 30mg per day appears to be the sweet spot
• Beginners typically start with 10–15mg/day
• Advanced users often push 20–30mg/day, split into two doses

Half-Life:

• Estimated to be around 6–8 hours, meaning twice-daily dosing is preferred for stable plasma levels

Compared to longer-lasting SARMs like LGD-4033 or Ostarine, AC-262 needs more frequent dosing — but that’s manageable if you’re running a serious cycle.