YK11

ID: yk11

Aliases: YK-11, Myostine

Type: compound

Route/form: oral preclinical SARM-like context

Status: research

Evidence level: preclinical

Best data tier: non-human experimental

Support scope: non-human/mechanistic

Source types: in_vitro, mechanistic, preclinical

Linked sources: 5

Broad outcomes: Fat loss / metabolic health, Muscle growth / performance / recovery, PEDs / AAS / thermogenics, Safety / regulatory

Reading note: These are curation notes anchored to linked sources, not a clinical recommendation or protocol.

Targets / mechanism

• androgen receptor partial agonist
• follistatin induction
• myostatin pathway modulation claim

Optimization domains

• SARM
• myostatin
• body composition
• doping
• unapproved context

Research basis

• In vitro work links YK11 to AR-mediated myogenic differentiation and follistatin expression, explaining why optimization discussions frame it as a SARM/myostatin hybrid.
• Additional mechanistic work shows gene-selective AR DNA-binding/cofactor recruitment, so it should not be treated as interchangeable with nonsteroidal SARMs.
• Osteoblast and other preclinical data provide broader tissue-biology leads, but they remain far from human hypertrophy evidence.

Limits, risks, and missing evidence

• Human efficacy and safety data are absent; the core evidence is cell-level, animal, and toxicology-oriented.
• Rodent/integrated preclinical hippocampal studies raise oxidative-stress, mitochondrial, and neurofunction concerns rather than clean performance support.
• Follistatin/myostatin-pathway language is mechanistically interesting but not a controlled human hypertrophy result.

Risk flags

• research compound
• preclinical only
• neurotoxicity signal
• oxidative stress signal
• sarm class risk
• product identity risk

Linked papers, labels, and reviews

1. YK11 regulates myogenic differentiation by follistatin expression
   in_vitro / pubmed_yk11_follistatin_2013
   C2C12 myoblast work underlying YK11 follistatin/myostatin claims.
2. YK11 induces oxidative stress and mitochondrial dysfunction in hippocampus: The interplay between a selective androgen receptor modulator (SARM) and exercise
   preclinical / pubmed_yk11_hippocampus_oxidative_stress_2023
   Rat hippocampus oxidative-stress/mitochondrial source; important safety counterweight for YK11 forum claims.
3. Selective Androgen Receptor Modulator, YK11, Up-Regulates Osteoblastic Proliferation and Differentiation in MC3T3-E1 Cells
   in_vitro / pubmed_yk11_osteoblasts_2018
   Osteoblast cell source; supports broader AR/follistatin biology but remains non-human.
4. From gains to gaps? How Selective Androgen Receptor Modulator (SARM) YK11 impact hippocampal function: In silico, in vivo, and ex vivo perspectives
   preclinical / pubmed_yk11_hippocampal_function_2024
   Integrated preclinical/in silico hippocampal-function source for YK11 safety concerns.
5. Differential DNA-binding and cofactor recruitment are possible determinants of the synthetic steroid YK11-dependent gene expression by androgen receptor
   mechanistic / pubmed_yk11_ar_cofactor_dna_binding_2022
   Mechanistic AR DNA-binding/cofactor-recruitment source; helps explain why YK11 is not interchangeable with nonsteroidal SARMs.