Anabolism: which is beter? Ostarine or NPP?

[PCaWarrior]

Comparison of Ostarine (5 mg/day) vs. NPP (250 mg/week) in High-T pBAT

Anabolic Effects

Parameter Ostarine (5 mg/day) NPP (250 mg/week)

AR Activation Selective (muscle/bone) Non-selective (systemic)

Anabolic:Androgenic Ratio ~10:1 (low androgenic risk) ~10:1 (converts to DHN, weaker than DHT)

Lean Mass Gain ~1–2 kg over 12 weeks (preclinical) ~3–5 kg over 12 weeks (clinical)

Mechanism Partial AR agonism, no aromatization Full AR agonism, no estrogen conversion

Risks

Risk Factor Ostarine (5 mg/day) NPP (250 mg/week)

Hepatotoxicity Low (mild ALT elevation in 10–15%) Very low (no liver toxicity reported)

Hormonal Suppression Mild (reversible) Moderate (requires PCT post-cycle)

Cardiovascular HDL ↓15–20%, LDL ↑10% HDL ↓20–30%, LDL ↑15%

Androgenic Side Effects None (no DHT conversion) Mild (acne, hair loss in sensitive users)

Estrogenic Effects None None (non-aromatizable)

Interaction With pBAT (High-T Environment)

Ostarine:

Synergy: May enhance AR signaling in muscle without competing with supraphysiologic T.

Risk: Unlikely to interfere with pBAT’s AR overload strategy.

NPP:

Synergy: DHN (weak androgen) minimizes interference with pBAT’s AR dynamics.

Risk: May blunt T-induced AR overload by stabilizing AR dimers.

Key Takeaways

Anabolism: NPP (250 mg/week) offers 2–3× greater muscle gain than Ostarine (5 mg/day).

Safety: Ostarine has lower cardiovascular risk; NPP avoids estrogenic/hepatic issues.

pBAT Compatibility:

Ostarine: Ideal for low-androgen, muscle-sparing support.

NPP: Better for rapid hypertrophy but may reduce pBAT’s AR stress benefits.

Recommendation:

For maximal muscle gain with pBAT: NPP 250 mg/week.

For minimal side effects, take Ostarine 5 mg/day.

If I was doing ADT and wanted to add an anabolic, I'd add Ostarine. Much lower risk. During pBAT high-T I sometimes use NPP and sometimes use Ostarine or Rad. Or I take both.

[TooMuchTax]

Interesting post Warrior. I had recently wondered about whether nandrolone decanoate (ND - the longer ester version of NPP) could be a viable adjunct to androgen deprivation therapy (ADT).

In particular, I wondered why ND isn't used (or seemingly even tested) as part of a prostate cancer treatment regimen to offset ADT's muscle catabolism. I speculated using ND could be advantageous since it would likely (1) suppress a person's natural testosterone, (2) promote muscle anabolism and (3) aromatize into DHN rather than DHT.

Seems like a "win-win-win" scenario to me.

[PCaWarrior in reply to TooMuchTax]

NPP is a weak ARSI in a way (DHN blocking DHT). But it becomes a weak AR stimulant if you are on ADT. And if you use an ARSI like Nubeqa it probably doesn't work. I tried it with an ARSI and I didn't notice the usual anabolism.

It would be interesting to study it with active surveillance for the reasons you mention.