YK-11

A steroidal compound sold under the SARM label. YK-11 acts on the androgen receptor, a cell signal responsive to testosterone. It is not a peptide and differs structurally from non-steroidal SARMs such as RAD-140 and LGD-4033. Kanno 2013: follistatin in cultured mouse muscle cells (Animal context · Accessed 2026-09-30)

The myostatin story is a theory about muscle growth. Myostatin helps limit muscle growth; follistatin can interfere with that signal. Bodybuilding discussion calls YK-11 a way to remove the brake. That possibility is not established in people. Derek's YK11 overview and unknown half-life (Community guide · Accessed 2026-09-30)

Mouse cells explain the follistatin interest. The 2013 experiment used cultured mouse muscle cells, not trained people. It does not supply a human dose, a muscle-gain prediction or a half-life. Kanno 2013: follistatin in cultured mouse muscle cells (Animal context · Accessed 2026-09-30)

Source context — Kanno 2013: follistatin in cultured mouse muscle cells: In-vitro mouse-cell context; allowed animal_context source kind used for species-labeled laboratory evidence. No human efficacy, safe amount, onset or half-life.

Source context — Derek's YK11 overview and unknown half-life: Creator bodybuilding explainer with affiliate/product promotion. General claims and suggestions are not controlled data; outdated no-human-study wording conflicts with later metabolite research.

A drier, more vascular appearance. An oral 10 mg/day month with MK-677 brought a reported dense look and estimated body-composition changes, but no strength improvement. The author explicitly credited hard training and diet too. Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30)

Size and strength gains are possible reports, not a forecast. A six-week solo account claimed 15 lb gained and large lift increases, while returning after injury, eating a calorie surplus and training frequently. Commenters highlighted muscle memory. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30)

The dramatic transformation is also a training-return story. The author aimed for an 800-calorie surplus while regaining lost size after injury. Later retention and late-course fatigue are parts of that person's story, not independent corroboration. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30)

Joint pain can undermine the reason for using it. The six-week reporter had aches and a stiff neck late in the course. A different oral contributor reported no new muscle or strength, only dry, stiff joints that hindered workouts. Neither proves a specific tendon mechanism. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30) · Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30)

Unchanged results are part of the picture. The oral 10 mg nonresponder and the MK-677-stacked author with unchanged strength are different people. A pill-stack commenter also could not tell whether YK-11 added anything after four weeks. Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30) · Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30)

Source context — Oral YK-11: nonresponse, a month with MK-677, and route disputes: Separate users in one thread. Unverified labels, subjective estimates and co-use; commenters' pharmacology assertions are not measurements.

Source context — Six-week solo YK-11 transformation and follow-up: Anonymous self-report with unverified product and unstated route; prior injury, training return and calorie surplus confound gains. Same-author follow-up is one account; no independently reviewed bloodwork.

Source context — Eight-week pill plan, updates and a separate injected account: OP and commenters are distinct. Planned escalation and course length are not completed outcomes. Measurements fluctuate; edited posts and unverified products. No syringe/preparation or PCT recipes reproduced.

Oral chart talk: about 5–10 mg/day. Community charts describe a daily total, sometimes split. One pill logger used 10 mg/day each morning. These are reported practices, not an approved therapeutic dose. Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30)

One six-week account used 10 mg/day, then 15 mg/day. The author specified 5 mg twice daily in weeks 1–3, then 7.5 mg twice daily in weeks 4–6. Route was unstated; joint pain troubled the higher-dose period. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30)

Other amounts must stay with their routes. A retrospective report used 10 mg morning and 10 mg later, without stating route. The sublingual log used 5 mg twice daily, totaling 10 mg/day. Neither establishes a better amount. Retrospective six-week split-dose account (Community discussion · Accessed 2026-09-30) · RAD-140 plus sublingual YK-11 log (Personal report · Accessed 2026-09-30)

An injected report used 2.5 mg twice daily: 5 mg/day. A separate intramuscular commenter also used Cardarine. The thread author took pills. This cannot validate equivalent oral dosing or injection safety. Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30)

Oral, sublingual and injected reports describe different exposures. Reports describe swallowed pills, liquid held under the tongue and intramuscular products. Their labels do not establish equivalent absorption, verified contents or interchangeable amounts. Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30) · RAD-140 plus sublingual YK-11 log (Personal report · Accessed 2026-09-30)

Source context — Eight-week pill plan, updates and a separate injected account: OP and commenters are distinct. Planned escalation and course length are not completed outcomes. Measurements fluctuate; edited posts and unverified products. No syringe/preparation or PCT recipes reproduced.

Source context — Six-week solo YK-11 transformation and follow-up: Anonymous self-report with unverified product and unstated route; prior injury, training return and calorie surplus confound gains. Same-author follow-up is one account; no independently reviewed bloodwork.

Source context — Retrospective six-week split-dose account: Route and actual laboratory values not supplied. Retrospective anonymous account; favorable bloodwork claim is not independently checked. Absolute publication date not recovered from opened body.

Source context — RAD-140 plus sublingual YK-11 log: Reposted same-person log, not an independent second story; illness, training and co-agents confound it. Strength values include calculated estimates. Absolute publication date not recovered from opened body.

No change on day one; a strong pump by day six in one log. This followed sublingual YK-11 added to RAD-140, with illness and another medication change. It is one experience, not a reliable onset interval. RAD-140 plus sublingual YK-11 log (Personal report · Accessed 2026-09-30)

Early reports also include no distinct effect. Oral reports span no noticeable change through pumps or vascularity in the first week. No controlled window establishes when muscle growth should begin.

A single-dose benefit window is not established. Accounts track workouts and weeks, not one administration's beginning and end. A split-dose contributor described a pumped appearance on rest days; this does not prove all-day drug action. Retrospective six-week split-dose account (Community discussion · Accessed 2026-09-30)

One author retained strength and most size after the course. The six-week reporter said some fullness disappeared after post-cycle treatment. The follow-up interval and independently reviewed laboratory results were not supplied. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30)

Unknown in the inspected community sources. More Plates More Dates calls it unknown while proposing split dosing. That suggestion is speculative; dosing habits do not measure how quickly the body eliminates YK-11. Derek's YK11 overview and unknown half-life (Community guide · Accessed 2026-09-30)

Urinary detection is different from half-life. A human elimination study found no intact YK-11 in collected urine. Unconjugated breakdown products disappeared within 24 hours; conjugated products remained detectable beyond 48 hours. These are detection observations, not felt duration, an elimination half-life or a clearance guarantee. Piper et al. 2018 human YK-11 metabolite-detection study (Official context · Accessed 2026-09-30)

Source context — RAD-140 plus sublingual YK-11 log: Reposted same-person log, not an independent second story; illness, training and co-agents confound it. Strength values include calculated estimates. Absolute publication date not recovered from opened body.

Source context — Retrospective six-week split-dose account: Route and actual laboratory values not supplied. Retrospective anonymous account; favorable bloodwork claim is not independently checked. Absolute publication date not recovered from opened body.

Source context — Six-week solo YK-11 transformation and follow-up: Anonymous self-report with unverified product and unstated route; prior injury, training return and calorie surplus confound gains. Same-author follow-up is one account; no independently reviewed bloodwork.

Source context — Derek's YK11 overview and unknown half-life: Creator bodybuilding explainer with affiliate/product promotion. General claims and suggestions are not controlled data; outdated no-human-study wording conflicts with later metabolite research.

Source context — Piper et al. 2018 human YK-11 metabolite-detection study: Abstract only. Dose, route and participant count absent there; urinary detection cannot quantify plasma half-life, benefit duration or anti-doping clearance.

Four-, six- and eight-week discussions are different examples. The MK-677 account lasted a month; the solo transformation lasted six weeks. The pill logger planned eight weeks but mentioned post-cycle treatment in week seven after illness. A plan is not a completed course. Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30) · Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30) · Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30)

Some courses end because training becomes painful. The sublingual author dropped YK-11 during its third week of exposure because of shoulder and lower-back pain. There is no established safe course length, recovery interval or long-term schedule in these accounts. RAD-140 plus sublingual YK-11 log (Personal report · Accessed 2026-09-30)

PCT means post-cycle treatment, not guaranteed recovery. Discussion adds other hormonal drugs during or after courses. Co-use changes libido, mood and laboratory results; a PCT story cannot prove natural testosterone production recovered. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30) · RAD-140 plus sublingual YK-11 log (Personal report · Accessed 2026-09-30)

Source context — Oral YK-11: nonresponse, a month with MK-677, and route disputes: Separate users in one thread. Unverified labels, subjective estimates and co-use; commenters' pharmacology assertions are not measurements.

Source context — Six-week solo YK-11 transformation and follow-up: Anonymous self-report with unverified product and unstated route; prior injury, training return and calorie surplus confound gains. Same-author follow-up is one account; no independently reviewed bloodwork.

Source context — Eight-week pill plan, updates and a separate injected account: OP and commenters are distinct. Planned escalation and course length are not completed outcomes. Measurements fluctuate; edited posts and unverified products. No syringe/preparation or PCT recipes reproduced.

Source context — RAD-140 plus sublingual YK-11 log: Reposted same-person log, not an independent second story; illness, training and co-agents confound it. Strength values include calculated estimates. Absolute publication date not recovered from opened body.

With RAD-140 / LGD: Common SARM stack talk — multiplies unknowns. [community]

A drier, more vascular appearance. An oral 10 mg/day month with MK-677 brought a reported dense look and estimated body-composition changes, but no strength improvement. The author explicitly credited hard training and diet too. Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30)

Pumps can change without an acute strength boost. A sublingual stack log described pumps and hunger, without clear immediate strength gains. RAD-140 and changed enclomiphene use complicate attribution. RAD-140 plus sublingual YK-11 log (Personal report · Accessed 2026-09-30)

An injected report used 2.5 mg twice daily: 5 mg/day. A separate intramuscular commenter also used Cardarine. The thread author took pills. This cannot validate equivalent oral dosing or injection safety. Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30)

Vepmor94 post and replies: oral pills 10 mg/day line 216, DHEA/ZMA/creatine co-use, tendon pain week 4 lines 110–155, week 7 illness/PCT update 167–200. Deleted commenter line 207: intramuscular 2.5 mg twice daily, total 5 mg/day, Cardarine co-use. FrostyPlay9924 lines 234–239: uncertain benefit at 10 mg/day oral with product named rad150. Eight-week pill plan, updates and a separate injected account (Community discussion · Accessed 2026-09-30)

Source context — Oral YK-11: nonresponse, a month with MK-677, and route disputes: Separate users in one thread. Unverified labels, subjective estimates and co-use; commenters' pharmacology assertions are not measurements.

Source context — RAD-140 plus sublingual YK-11 log: Reposted same-person log, not an independent second story; illness, training and co-agents confound it. Strength values include calculated estimates. Absolute publication date not recovered from opened body.

Source context — Eight-week pill plan, updates and a separate injected account: OP and commenters are distinct. Planned escalation and course length are not completed outcomes. Measurements fluctuate; edited posts and unverified products. No syringe/preparation or PCT recipes reproduced.

Joint pain can undermine the reason for using it. The six-week reporter had aches and a stiff neck late in the course. A different oral contributor reported no new muscle or strength, only dry, stiff joints that hindered workouts. Neither proves a specific tendon mechanism. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30) · Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30)

Low libido, fatigue, acne and hair shedding appear together. The solo reporter described feeling suppressed and struggling to train or get up for work. These symptoms raise hormonal concerns, but symptoms alone do not measure testosterone suppression. Another retrospective contributor reported no side effects. Six-week solo YK-11 transformation and follow-up (Community discussion · Accessed 2026-09-30) · Retrospective six-week split-dose account (Community discussion · Accessed 2026-09-30)

Mood and chest symptoms also appear in a forum account. On AnabolicMinds, two contributors described chest tightness or a fast heartbeat; one also described moodiness. Their stated amounts and incomplete co-use details cannot establish causation or a safe threshold. AnabolicMinds Yk11 discussion (Community discussion · Accessed 2026-09-30)

Liver, lipids and long-term effects remain concerns. Claims that injections eliminate liver risk are disputed in the oral-versus-injected thread and unsupported by a controlled comparison. Long-term use is poorly characterized. Oral YK-11: nonresponse, a month with MK-677, and route disputes (Community discussion · Accessed 2026-09-30)

A label may omit other active substances. FDA found labeled YK-11 plus undeclared trendione in Ykarine after a stroke report. That finding does not establish which ingredient caused the event. FDA warning: SARM products and Ykarine analysis (Official context · Accessed 2026-09-30)

Unapproved products carry risks beyond the named ingredient. FDA warns that SARM products are unapproved drugs, not dietary supplements, and lists serious liver, cardiovascular, reproductive and pregnancy risks. Chest pain, breathing difficulty, jaundice or dark urine need medical assessment. FDA warning: SARM products and Ykarine analysis (Official context · Accessed 2026-09-30)

Source context — Six-week solo YK-11 transformation and follow-up: Anonymous self-report with unverified product and unstated route; prior injury, training return and calorie surplus confound gains. Same-author follow-up is one account; no independently reviewed bloodwork.

Source context — Oral YK-11: nonresponse, a month with MK-677, and route disputes: Separate users in one thread. Unverified labels, subjective estimates and co-use; commenters' pharmacology assertions are not measurements.

Source context — Retrospective six-week split-dose account: Route and actual laboratory values not supplied. Retrospective anonymous account; favorable bloodwork claim is not independently checked. Absolute publication date not recovered from opened body.

Source context — AnabolicMinds Yk11 discussion: Route/co-use not fully established in inspected excerpt; no causal diagnosis or verified product. Forum has commercial banners; opinions include unsupported endocrine/mechanism assertions.

Source context — FDA warning: SARM products and Ykarine analysis: Class/product warning, not a YK-11-specific controlled incidence study. The tested product also contained undeclared trendione; event attribution remains uncertain.