Partial SARM • Oral • Emerging Research

ACP-105: The Milder SARM With Neuroprotective Interest

Last updated: March 2026

ACP-105 is a partial androgen receptor agonist developed by Acadia Pharmaceuticals. Milder than LGD-4033 or RAD-140, it occupies the low-potency end of the SARM spectrum. Research interest includes muscle preservation, bone density, and emerging neuroprotective applications. All data from preclinical animal models.

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Anecdotal Research Dose
Oral, once daily
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AR Agonist Class
Not full activation
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Suppression Profile
Lower than LGD/RAD

How ACP-105 Works

ACP-105 is a selective androgen receptor modulator that binds AR with high affinity but acts as a partial agonist — it initiates receptor signaling but does not maximally activate the receptor. This partial activation profile is theorized to deliver anabolic effects with reduced androgenic and suppressive activity versus full agonists.

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Partial AR Agonism

ACP-105 binds the androgen receptor with high selectivity but functions as a partial agonist. Unlike full agonists (testosterone, LGD-4033), it activates only a fraction of the receptor's signaling cascade. This results in lower anabolic potency but also reduced androgenic stimulation in non-target tissues like the prostate.

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Muscle & Bone Activity

In rodent studies, ACP-105 demonstrated muscle weight preservation in castrated male models and supported bone mineral density at doses lower than testosterone. The anabolic-to-androgenic selectivity ratio appears favorable compared to testosterone in preclinical data, though less potent than full SARM agonists.

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Neuroprotective Potential

Androgen receptors are expressed throughout the CNS. Some animal studies have explored ACP-105 for cognitive and neuroprotective effects — particularly in aging and injury models. Acadia Pharmaceuticals' original interest partly included CNS applications. This represents very early-stage research with no human data.

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Reduced Suppression vs Full Agonists

Partial agonism theoretically reduces HPG axis suppression relative to full AR agonists like LGD-4033. ACP-105 may cause milder testosterone suppression at equivalent anabolic doses, though suppression still occurs and post-cycle considerations remain. Exact suppression magnitude in humans is uncharacterized.

What Preclinical Studies Show

⚠️ All data below is from animal studies (rodent models). ACP-105 lacks human clinical trial data. Figures represent preclinical findings only.

Levator Ani Muscle Preservation (vs castration)
Muscle mass in castrated rat model — animal study
Significant
Anabolic:Androgenic Ratio vs Testosterone
Selectivity in rodent models — animal study
Favorable
Bone Mineral Density Support
Osteoporosis model — animal study
Observed
Prostate Weight vs Testosterone
Androgenic activity at muscle-equivalent dose — animal study
Lower
HPG Axis Suppression
LH/FSH impact at research doses — animal data
Mild–Moderate

Side Effects & Risks

Testosterone Suppression
Expected — milder than full agonist SARMs
Mild
Androgenic Side Effects (acne/hair)
Partial agonism reduces androgenic signal
Low
Liver Enzyme Elevation
Monitor ALT/AST — class effect
Unknown
Long-Term Safety
No chronic human studies exist
Unknown

Key Takeaways

✅ What We Know
  • Partial AR agonist with anabolic selectivity in preclinical models
  • Milder than LGD-4033 and RAD-140 in potency and suppression
  • Oral bioavailability confirmed in animal models
  • Emerging interest in neuroprotective applications
  • Favorable anabolic:androgenic ratio vs testosterone in rodents
⚠️ What We Don't Know
  • No approved human clinical trials completed
  • Exact suppression magnitude in humans is uncharacterized
  • Long-term safety profile unknown
  • Whether neuroprotective effects translate to humans

🛒 Recommended Products

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⚠️ Important Disclaimer

This page is for educational purposes only. It is not medical advice. ACP-105 is not FDA approved and is not intended for human use. All data referenced is from preclinical animal studies. Do not use any research chemical without consulting a qualified medical professional.