STUDresearch · Non-peptide
YK-11
Also known as
YK11 · myostatin SARM · YK-11 · YK 11 · Myostine (research-commerce / Health Canada nickname) · Myobol (forum/vendor nickname) · myostatin-related SARM discussion · (17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester · ykl-11
Community talk. May be wrong. Not medical advice. Not a protocol. Not for human or animal use.
Non-peptide
Some talk
Systemic
Oral
Performance / endurance
Systemic myostatin-pathway research chem.
What people say
YK-11 is an experimental steroidal androgen-receptor partial agonist. Its follistatin and myogenic findings come from mouse-cell work, not human muscle trials, and it is not an approved SARM medicine.
Doses people talk about
These rows document distinct reports, not a ladder. Product identity, co-agents, training state and cycle history differ, so the amounts are not directly comparable.
How it may feel
Reports conflict: pump, vascularity or a dry look appear in some accounts, while others describe no strength increase, joint pain, stiffness, acne, hair loss or low libido. One six-week author later said strength and most size persisted after PCT but some fullness faded; training, other compounds and unknown product identity remain major confounders.
Preserved oral discussion band~5–10 mg/day oral
Community notes describe once-daily or split use; the range is not tied to a controlled human dose study.
One-month multi-agent report10 mg/day oral
The author also used MK-677, trained and dieted hard, reported a dry/vascular look and achy joints, and said much of the change could be non-drug.
Six-week escalation report5 mg twice daily in weeks 1–3; 7.5 mg twice daily in weeks 4–6; route not stated
Joint pain and stiff neck affected the last three weeks, with acne, hair loss and low libido in the final 2–3 weeks; after PCT the author later reported retaining strength and most size but losing some fullness, with return-to-training and muscle-memory confounding.
Retrospective split-dose report20 mg/day split as 10 mg morning + 10 mg later
One author reported six weeks, a pumped or vascular look and no self-reported side effects; product identity and bloodwork were not independently verified.
Half-life & effect duration
- Half-life in the body
- Parent YK-11No settled estimate
- Felt duration people report
- AccountsPumps, vascularity, joint symptoms or other changes within weeks; experiences differ
Cycles people discuss
Forum culture commonly discusses six-to-eight-week oral runs, often with other SARMs or PCT language. Those are self-imposed practices, not clinical schedules.
Timing
Reported oral schedules include once-daily use, split morning/later doses, and one six-week escalation from 5 mg twice daily in weeks 1–3 to 7.5 mg twice daily in weeks 4–6. These are self-imposed forum schedules, not a clinical or PK-based calendar.
Stacks
YK-11 is often discussed with RAD-140, LGD-4033 or other performance drugs. Actual multi-agent reports cannot isolate its contribution or safety profile.
Watch for
Suppression lore: HPTA suppression concerns in community — treat seriously.
Tap a line to jump into the full notes. Research only — may be wrong.
Timing context & sources
Half-life in the body
No parent-drug human elimination half-life is established for YK-11.
A human anti-doping elimination study found urinary metabolites for more than 48 hours but no intact YK-11 in post-administration urine; the abstract does not report plasma PK.
Urinary metabolite detectability is not a parent-compound half-life, and the accessed abstract omits dose, route and participant count.
- Studies on the in vivo metabolism of the SARM YK11 (opens in a new tab)Read the PubMed abstract and metadata: an elimination study detected 14 deuterated urinary metabolites; no intact YK11 in post-administration urine; unconjugated metabolites disappeared within 24 hours and conjugates remained traceable beyond 48 hours.Anti-doping metabolite-detection study; the accessed abstract does not state dose, route, participant count, plasma PK or parent-drug half-life.
Felt duration people report
Forum reports place pump, vascularity, joint symptoms or other effects within weeks, but the direction and magnitude are inconsistent.
Reviewed accounts span a 10 mg/day oral multi-agent month, a six-week 5 mg twice-daily to 7.5 mg twice-daily escalation with unstated route, and a retrospective 20 mg/day split report.
Anonymous uncontrolled reports, unverified identity, varying co-agents and training state, no blinded outcomes and only one limited post-PCT durability update.
- YK-11 one-month oral stack report (opens in a new tab)Read the full discussion and report: one author described 10 mg/day oral YK-11 with MK-677 for one month, a dry/vascular look, no strength increase, dry/achy joints, and explicitly said hard training and diet could explain much of the change.Multi-agent, uncontrolled, self-reported body-composition estimates with unverified identity and no same-author laboratory follow-up.
- Six-week YK-11 transformation final update (opens in a new tab)Read the complete post and same-author replies: solo YK-11 was reported as 5 mg twice daily in weeks 1–3 and 7.5 mg twice daily in weeks 4–6; joint pain and stiff neck affected the last three weeks, with acne, hair loss and low libido in the last 2–3 weeks. After PCT the author later reported retaining strength and most size but losing some fullness; commenters identified return-to-training and muscle-memory confounding.Self-selected report, unverified product, no control, training-return and muscle-memory confounding, and incomplete route detail in the accessed discussion.
- YK-11 experiences and split-dose report (opens in a new tab)Read the thread, including one author's past six-week report of 20 mg/day split 10 mg morning and 10 mg later, a pumped/vascular look and no self-reported side effects.Retrospective anonymous report, unverified product, no controlled comparator and no independently reviewed bloodwork.
Other context in this card
- Selective androgen receptor modulator YK11 regulates myogenic differentiation of C2C12 myoblasts by follistatin expression (opens in a new tab)Read the PubMed abstract and metadata: YK11 induced follistatin expression and myogenic differentiation in mouse C2C12 cells; no human efficacy or pharmacokinetic endpoint was studied.In-vitro mouse-cell study; it does not establish human muscle growth, dose, onset, safety or half-life.
- FDA warning on bodybuilding products containing SARMs and YK-11 (opens in a new tab)Read the complete FDA consumer warning, including laboratory confirmation of YK-11 in Ykarine and the linked adverse-event context; FDA states SARMs products are unapproved and have not been reviewed for safety and effectiveness.Product warning and adverse-event context, not proof that YK-11 caused the reported stroke or a controlled incidence estimate.
What people say
- Muscle gain talk: Anecdotes of lean mass and hardness; confounded by training/diet/other agents. anecdote
- Body-comp talk: YK-11 is discussed for recomp, strength continuity, or soft-tissue recovery depending on class. forum
- Training confound: PRs and scale changes almost always co-travel with diet phase and programming. anecdote
- Suppression / lipid chatter: Hormonal agents pull bloodwork and PCT conversations even when marketed “mild.” forum
- Cycle thinking: Fixed on/off blocks dominate over indefinite daily use. forum
Doses people talk about
- Community oral bands: Often ~5–10 mg/day discussed; some split dosing. forum
- Quality flag: Assume label accuracy only if analytically verified — gray market fill error is common. forum
- Product quality: Gray-market fill accuracy and identity are uncertain; dose math assumes the label is true. forum
- Route changes the math: Oral vs SC vs nasal are not interchangeable milligram-for-milligram stories. forum
- Oral charts: Common chatter ~5–10 mg/day; PCT talk rides along like AAS culture. forum
- Start conservative (community): When people experiment, they often start at the low end of a charted band to gauge tolerance — still not advice. forum
- Framing: All figures are discussed trial, clinic, or community amounts — research/educational only, not prescriptions. forum
- Not medical: No approved therapeutic dose. forum
How it may feel
- Days 1–7: Oral reports range from no distinct effect to early pump, vascularity or training intensity; stack overlap and gray-market identity make attribution weak. forum
- Weeks 1–6: One 10 mg/day oral multi-agent month described a dry/vascular look, no strength increase and dry or achy joints. A separate six-week report used 5 mg twice daily for weeks 1–3 then 7.5 mg twice daily for weeks 4–6, with joint pain during the last three weeks, acne, hair loss and low libido in the last 2–3 weeks; after PCT the author later reported retaining strength and most size but losing some fullness. forumanecdote
- Weeks 6–8: Typical self-imposed cycle length talk. forum
- First days: No controlled onset window exists; forum claims that YK-11 “kicks in” quickly are subjective and are not pharmacokinetic evidence. forum
- Days 2–7: Side-effect window for many agents; benefits, if any, are easy to mis-attribute. forum
Cycles people discuss
- Length: Commonly 6–8 weeks then PCT-style talk in AAS culture forums. forum
- Common pattern: Many self-protocols use weeks-on / weeks-off rather than indefinite daily use — cost and caution drive this more than hard science. forum
- No magic cycle: There is rarely one universal “correct” on/off calendar across forums. forum
- Reassess: Stop and reassess if adverse effects appear; this is not medical care. forum
Timing
- Timing: Often dosed 1–2× daily in charts. forum
- Timing practicalities: People time doses around side effects, training, and sleep more than perfect PK. forum
- Published timing: A human elimination study detected no intact YK-11 in post-administration urine; unconjugated metabolites disappeared within 24 hours and conjugated metabolites remained traceable beyond 48 hours. That is a detection window, not a parent-drug half-life. trial
More on what it is
- What it is: Steroidal SARM-like myostatin-pathway research chem (not a classic non-steroidal SARM). forum
- Why people care: Muscle growth / recomp lore via follistatin/myostatin narratives. forum
- Research posture: Educational summary of public discussion and literature themes only. forum
- Bro framing: Myostatin-pathway “looksmax SARM-ish” chem — loud on forums, thin on clean human RCTs. forum
- Evidence honesty: Human RCTs are not the foundation — mostly community + limited preclinical framing. forum
- Research only: Not approved advice for self-experimentation; legality and access vary by place. forum
Stacks
- With RAD-140 / LGD: Common SARM stack talk — multiplies unknowns. forum
- Less is clearer: Solo runs make personal n=1 easier to interpret than five-compound blasts. forum
Storage notes
- No mix instructions here: STUDresearch does not list reconstitution, diluent volumes, or syringe unit charts. People reconstitute many different ways and vial labels differ — that content creates more confusion than clarity. forum
- Storage (general talk only): Unopened research products are usually kept cool, dry, and away from light per the seller label. Anything after first use is product-specific — follow the label, not a universal forum SOP. forum
Watch for
- Suppression lore: HPTA suppression concerns in community — treat seriously. forum
- Joint dryness / aggression: Anecdotal. anecdote
- Liver/lipid unknowns: Oral research chem risk profile incomplete. forum
- Unknowns: Long-term safety for gray-market preparations is often poorly characterized. forum
- Stack noise: Sides logged on multi-agent stacks cannot be blamed cleanly on one compound. forum
- Seek care red flags: Severe allergic reaction, chest pain, neuro changes, or uncontrolled BP/glucose need real medical care — not forum advice. forum
- Unapproved-drug status: SARMs are not FDA-approved for human use and are not legal dietary-supplement ingredients. This card maps forum talk only — not a sourcing guide, not a safety claim, and not a promise of results. trial
- Product identity: FDA laboratory work confirmed YK-11 in one labeled bodybuilding product while also warning that SARM products are unapproved and may be of unknown quality. trial
Evidence mix
Mostly community / anecdote tags
Full: every bullet (trial + community). Use Scan for a faster bro-science read.