The Compound Report is an educational resource. Nothing on this site constitutes medical advice or encourages personal use of any compound. Always consult a qualified healthcare provider.
Educational reference only. Nothing on this page constitutes medical advice or encourages personal use of this compound. Always consult a qualified healthcare provider before any decision involving your health.
MK-677 is one of the most instructive case studies in drug development in this book. The compound does exactly what it's supposed to do — raise GH and IGF-1 persistently through oral dosing. The clinical endpoints failed anyway.
Merck Sharp & Dohme developed ibutamoren as part of a research program exploring ghrelin receptor agonism as a pharmacological strategy for age-related GH decline and its downstream consequences: sarcopenia, osteoporosis, metabolic changes of aging, and potentially cognitive decline. The mechanistic rationale was compelling: as GH secretion declines with age (the somatopause), restoring it pharmacologically should reverse some of the body composition changes associated with aging — reduced muscle mass, increased fat, reduced bone density. Injectable GH had shown these effects but required daily injections and came with significant adverse effects at replacement doses. An oral GHSR agonist that restored pulsatile GH release through the physiological pituitary machinery would be superior in theory. Merck tested MK-677 in six separate clinical indications: growth hormone deficiency, osteoporosis, hip fracture recovery, sarcopenia, obesity, and Alzheimer's disease. Across all of them, the biomarker response was consistent: GH and IGF-1 rose. Fat-free mass increased modestly. Then the clinical endpoints failed consistently to follow — no meaningful improvement in muscle strength, physical function, hip fracture outcomes, or cognitive function. The hip fracture trial was stopped early, in part due to apparent increases in congestive heart failure in elderly patients. No indication received NDA submission. The program was abandoned.
THE CENTRAL TENSION
MK-677 has one genuinely compelling advantage over every other compound in the GH secretagogue class: it is oral, once-daily, and well-tolerated enough for months of continuous use. Every other GH secretagogue in this book requires subcutaneous injection. This convenience advantage is real and pharmacologically meaningful — sustained IGF-1 elevation is well-documented in human trials, the pulsatile mechanism is preserved, and the sleep quality improvement is among the most consistently reported effects in community use. The problem: the compound that reliably raises IGF-1 did not translate this biomarker improvement into the clinical outcomes Merck was trying to demonstrate, and produced consistent glucose metabolism impairment across trial populations. The community uses it for sleep quality, modest body composition benefit, and general GH-axis optimization — applications where the evidence standard is lower than the Merck endpoints and where the benefit-risk calculation may be more favorable than it was in elderly hip fracture patients.
The most consistent safety signal across all MK-677 trials is glucose metabolism impairment. Mechanism: GH is a counter-regulatory hormone for insulin (antagonizes insulin action, increases hepatic glucose output); persistent 24-hour GHSR-1a agonism means persistent GH-mediated glucose metabolism impairment all day. Effect magnitude in Nass 2008: fasting glucose increased approximately 5 mg/dL at 25 mg/day; this is not clinically alarming in healthy adults but is pharmacologically meaningful and potentially significant in pre-diabetic or insulin-resistant individuals. The community should take this seriously: HbA1c monitoring at 3-6 months is appropriate; individuals with pre-existing insulin resistance, impaired fasting glucose, or T2D should not use MK-677 without physician oversight and glucose monitoring; combining MK-677 with HGH (both raise GH and IGF-1; both antagonize insulin) significantly amplifies glucose metabolism impairment.
GH causes sodium and water retention. At 25 mg/day MK-677, fluid retention producing ankle and hand edema is reported in clinical trials and is among the most common community complaints. The edema is typically mild, non-pitting, and resolves with dose reduction. It is more common in the first weeks of use before adaptation occurs. At higher community doses (50 mg/day) edema becomes more pronounced and can be clinically significant. Dose-dependent and reversible.
Ghrelin is the 'hunger hormone.' GHSR-1a agonism reliably increases appetite. At 25 mg/day, appetite increases are reported in most community users — often described as significantly elevated hunger, particularly in the first hours after dosing and before sleep. This appetite stimulation is why the 'lean mass gains' from MK-677 must be contextualized: if caloric intake increases in response to appetite stimulation, the net body composition change reflects the net caloric balance, not just the GH/IGF-1 effect. Community users who use MK-677 without managing food intake frequently gain fat alongside any lean mass gains — and the fat gain is compounded by the fluid retention-associated scale weight increase, creating disappointment when body composition measurements lag behind scale weight.
The CHF signal from the elderly hip fracture trial applies to a specific population: elderly patients (65+) with pre-existing cardiac compromise. It is mechanistically explained by the fluid retention burden of persistent GH-mediated sodium retention precipitating cardiac decompensation in patients with reduced cardiac reserve. This is NOT a contraindication for young, healthy adults with normal cardiac function. It IS a relevant consideration for: older adults (>60); any history of heart failure, reduced ejection fraction, or symptomatic cardiac disease; any condition that already compromises fluid management (renal impairment, liver cirrhosis). For these populations: physician evaluation before MK-677 use.
As with all GH-elevating compounds, MK-677 is absolutely contraindicated in active malignancy. Sustained IGF-1 elevation promotes cell proliferation and survival — in cancer cells as in normal cells. Additionally, MK-677's persistent 24-hour IGF-1 elevation may produce higher total IGF-1 exposure than injectable secretagogues that produce more pulsatile profiles. Monitor IGF-1 with the same SDS framework as HGH: do not allow persistent IGF-1 >+2 SDS for age/sex.
Unlike GHRP-2 and GHRP-6, which activate non-GHSR pathways and can produce notable prolactin and cortisol elevation, MK-677's high GHSR selectivity largely avoids these effects. Ipamorelin shares this advantage. Community-reported data and clinical trials confirm that MK-677 at 25 mg/day does not produce significant prolactin or cortisol elevation — an advantage over some other GHSR agonists.
The ghrelin receptor (growth hormone secretagogue receptor 1a, GHSR-1a) is a G-protein coupled receptor (GPCR) expressed in the pituitary somatotrophs, hypothalamus, and multiple peripheral tissues including the stomach, intestine, and heart. Endogenous ghrelin — a 28-amino acid peptide acylated at Ser3 with an octanoic acid group — is the primary natural ligand and was identified in 1999. Ghrelin is secreted primarily by the gastric fundus (hence it is known as the 'hunger hormone' — it rises before meals and falls after eating) and acts centrally to stimulate GH release and peripherally to drive appetite, promote fat storage, and modulate energy metabolism. The GHSR-1a is constitutively active at approximately 50% of its maximum response even in the absence of ghrelin — making it an unusual GPCR and explaining why GHSR-1a agonism has complex effects beyond simple GH stimulation.
MK-677 binds GHSR-1a in pituitary somatotrophs and hypothalamic neurons as a full agonist with higher affinity and selectivity than endogenous ghrelin. In pituitary somatotrophs: GHSR-1a activation → Gq/G11 coupling → phospholipase C activation → IP3 → intracellular calcium release → GH secretory granule exocytosis. This produces an increase in GH pulse amplitude (larger pulses) and to some extent pulse frequency. The hypothalamic component: GHSR-1a activation in the arcuate nucleus and other hypothalamic nuclei stimulates GHRH release and inhibits somatostatin release — both effects amplifying GH secretion. The synergy with GHRH is the most important clinical pharmacodynamic property: MK-677 acts synergistically with endogenous GHRH (and exogenous GHRH analogues like sermorelin) to amplify GH pulse amplitude. This is why MK-677 + GHRH analogue combinations are used in community protocols for maximum pulsatile GH release.
Ipamorelin, GHRP-2, and GHRP-6 are injectable GHSR-1a agonists with the same fundamental mechanism as MK-677. The pharmacokinetic difference is critical: injectable GHRPs have half-lives of 2-4 hours requiring multiple daily injections; each injection produces a discrete GH pulse that resolves before the next dose. MK-677's ~24-hour half-life produces sustained GHSR-1a receptor occupancy throughout the day and night, resulting in: enhanced pulsatile GH release (particularly the sleep-associated nocturnal pulse); sustained IGF-1 elevation (measurably elevated 24 hours a day at steady state, unlike injectable secretagogues where IGF-1 elevation is more time-limited); and persistent appetite stimulation (the ghrelin-pathway hunger effect is always present, not just for hours after injection). The 24-hour receptor occupancy is both the efficacy advantage (stable IGF-1 levels; reliable nocturnal GH pulse enhancement) and the side effect driver (constant appetite stimulation; sustained GH-mediated glucose antagonism).
MK-677 has more published Phase 2 and Phase 3 human data than most compounds in this book. The evidence shows what it does — and what it doesn't do.
Nass R, Pezzoli SS, Oliveri MC, et al. (2008). Effects of an Oral Ghrelin Mimetic on Body Composition and Clinical Outcomes in Healthy Older Adults: A Randomized, Controlled Trial. Annals of Internal Medicine. 149(9):601-611. Design: randomized, double-blind, placebo-controlled; n=65 healthy older adults (60-81 years); 25 mg/day MK-677 or placebo for 12 months. Primary outcomes: GH/IGF-1; fat-free mass; abdominal visceral fat. Results: GH 24-hour secretion significantly increased; IGF-1 significantly increased (comparable to levels in young adults); fat-free mass: +1.1 kg vs no change in placebo; abdominal visceral fat: decreased significantly vs placebo; fasting glucose increased ~5 mg/dL; insulin sensitivity declined; muscle strength: no significant improvement on any strength measure. Adverse events: edema, fluid retention, transient increase in appetite, fatigue; 3/32 participants on MK-677 developed transient mild hyperglycemia. This trial is the most frequently cited in community use justification and is the primary source of both the efficacy and safety framing for MK-677.
Multiple earlier Merck-sponsored Phase 2 trials established the pharmacological basis: Rudman et al. (1998, NEJM): hip fracture elderly patients; MK-677 improved bone density markers; the trial that produced the early positive signal; this trial population was also associated with the congestive heart failure signal in later analyses. Chapman IM et al. (1996, Journal of Clinical Endocrinology & Metabolism): healthy elderly men and women; single doses and 2-week continuous dosing; confirmed GH/IGF-1 increases at 10-50 mg; established dose-response; fasting glucose increases dose-dependent. Murphy MG et al. (1998): multiple doses in healthy elderly; confirmed sustained IGF-1 elevation with oral once-daily dosing; no improvement in strength.
Several MK-677 trials showed improvement in bone turnover markers (osteocalcin, bone alkaline phosphatase) and some bone density improvement in elderly patients. This was one of the more consistent benefit signals. However, the bone density improvement in absolute terms was modest, and the primary endpoint of hip fracture recovery (the intended clinical application) was not definitively met before the program was discontinued. The bone density data represents the most consistent positive clinical signal beyond the body composition findings.
In Merck's elderly hip fracture trial, there was an apparent increase in congestive heart failure events in the MK-677 arm that contributed to early trial termination. The mechanism proposed: GH causes sodium retention and fluid retention; MK-677's persistent GHSR-1a agonism sustains GH-mediated sodium retention 24 hours a day; in elderly patients with compromised cardiac reserve, this fluid retention burden can precipitate CHF decompensation. This signal is specific to: elderly patients (65+); pre-existing cardiac compromise; prolonged continuous dosing. The community user population (generally younger, no cardiac compromise) is not the population where this signal was observed. But the signal informs the contraindications — any history of heart failure or cardiac dysfunction requires physician assessment before MK-677 use.
Study
Grade
Key Finding
Clinical Implication
Nass 2008 (Ann Intern Med)
B — RCT, n=65, 12 months
GH/IGF-1↑; FFM +1.1kg; visceral fat↓; no strength improvement; fasting glucose +5 mg/dL; insulin sensitivity↓
Primary community evidence; benefit for body composition but not strength; glucose monitoring required
Chapman 1996 (JCEM)
B — dose-ranging RCT
Dose-response confirmed for GH/IGF-1 at 10-50 mg; 25 mg standard dose established
Confirmed oral bioavailability and sustained IGF-1 elevation dose-response
Murphy 1998 series
B — Phase 2 RCT
Sustained IGF-1 elevation; no strength improvement; bone markers improved
Consistent pattern: biomarker success, functional endpoint failure
Rudman 1998 (NEJM)
B — Phase 2 elderly
Hip fracture bone density; earlier positive signal; CHF signal emerged in this population
Most important safety signal context; elderly + cardiac compromise = CHF risk
Alzheimer's Phase 3
B (negative)
No cognitive benefit despite robust IGF-1 elevation
IGF-1 elevation does not translate to cognitive benefit
Phase 3 discontinuation
Historical
Merck discontinued development after functional endpoint failures across indications
No NDA submitted; regulatory dead end; community use is entirely gray-market
While the body composition and strength benefits of MK-677 are modest and contested, the sleep quality improvement is the most consistently reported effect in both clinical research and community use — and it has the clearest mechanistic basis.
Ghrelin and GH are deeply interconnected with sleep architecture. The largest endogenous GH pulses occur during slow-wave sleep (SWS, or NREM Stage 3 sleep). Ghrelin receptor activation promotes SWS — the connection between ghrelin, sleep, and GH is bidirectional and mutual. MK-677's GHSR-1a agonism enhances the nocturnal GH pulse that normally occurs during SWS onset, and appears to promote SWS duration itself. Community users consistently report: improved sleep quality with more vivid and memorable dreams; deeper sleep with more refreshed waking; improved REM sleep and dream vividness (the GH-SWS connection enhances both SWS and the subsequent REM rebound). The clinical studies documented improvements in REM sleep duration and sleep quality scores. This sleep benefit is particularly relevant for older adults where SWS declines significantly with age — and where restoring the nocturnal GH pulse may have benefits for tissue repair, immune function, and cognitive consolidation during sleep.
The timing implication: for maximum sleep benefit, MK-677 should be taken approximately 1-2 hours before sleep. Some community users report initial sleep disruption in the first week (possibly from initial GH pulse enhancement disrupting existing sleep patterns) before sleep quality stabilizes and improves. The vivid dreams effect is pharmacologically consistent with the GH-REM enhancement and is reported by most users as a neutral-to-positive effect rather than disturbing.
Parameter
Guidance
Notes
Standard dose
25 mg/day oral
The dose used in all major clinical trials; higher doses increase side effects without clear additional benefit
Maximum community dose
50 mg/day
Increased edema, appetite, and glucose effects; not recommended as starting dose; marginal additional IGF-1 benefit over 25 mg
Timing
Evening, 1-2 hours before sleep
Maximizes the nocturnal GH pulse enhancement and sleep quality benefit; avoids daytime hunger disruption; allows glucose/insulin to recover between GH stimulation and main meals
Cycling
8-12 weeks on / 4-6 weeks off OR continuous with monitoring
Continuous use for months is used by many community members; cyclicity convention reflects concern about long-term receptor desensitization (poorly documented); no evidence-based cycle length; IGF-1 monitoring more important than arbitrary cycling
IGF-1 monitoring
Every 3-4 months; target 0 to +2 SDS for age/sex
Same as HGH monitoring framework; >+2 SDS = reduce dose or cycle off
Glucose/HbA1c
Baseline; 3 months; every 6 months
Fasting glucose expected to rise modestly; HbA1c monitoring catches sustained glucose perturbation; pre-diabetic individuals: more frequent monitoring
Appetite management
Caloric tracking essential, especially first 4-6 weeks
Appetite increase is the primary driver of unintended weight gain; users who don't track calories frequently gain fat; protein-forward diet minimizes fat gain while supporting lean mass effects
With food
On empty stomach or light protein-only snack preferred
High-carbohydrate meals before dosing blunt GH pulse response; fat may blunt ghrelin signaling; protein-only small meal is acceptable
THE SLEEP TIMING OPTIMIZATION
Taking MK-677 at bedtime is not just a safety recommendation to avoid daytime appetite disruption — it is pharmacodynamically optimal. The ghrelin receptor in hypothalamic circuits regulates sleep-wake cycles; GHSR-1a agonism promotes slow-wave sleep onset. The nocturnal GH pulse — the largest of the day in healthy physiology — is enhanced by GHSR-1a activation in conjunction with the natural GHRH surge during SWS onset. Evening dosing means the peak GHSR-1a receptor occupancy (3-4 hours post-dose) coincides with the critical SWS window. Morning dosing shifts the pharmacodynamic peak to the daytime, produces appetite stimulation during the active hours when users are trying to maintain caloric discipline, and misses the nocturnal GH pulse window. Always take MK-677 in the evening.
Feature
MK-677 (Ibutamoren)
Ipamorelin
CJC-1295 + Ipamorelin
GHRP-2 / GHRP-6
Route
Oral (unique advantage)
SubQ injection
SubQ injection
SubQ injection
Half-life
~24 hours
~2 hours
CJC-1295 DAC: ~8 days; CJC-no DAC: ~30 min
~2 hours
Receptor
GHSR-1a (ghrelin receptor)
GHSR-1a
CJC: GHRH receptor; Ipa: GHSR-1a
GHSR-1a (+ CD36 non-GHSR)
IGF-1 profile
Sustained 24hr elevation
Pulse-only; returns to baseline between doses
Sustained (CJC DAC); pulsatile (CJC no-DAC)
Pulse-only; multiple daily doses required for sustained IGF-1
Appetite stimulation
Significant (ghrelin mechanism; 24hr)
Mild (ghrelin mechanism; brief)
Mild (ipamorelin component)
GHRP-6: significant; GHRP-2: moderate
Prolactin/cortisol elevation
Minimal
Minimal
Minimal
GHRP-2: moderate; GHRP-6: notable
Sleep quality benefit
Significant (primary community benefit)
Mild (brief pulse)
Moderate
Moderate (GHRP-6 more sedating)
Glucose metabolism concern
Moderate — documented in trials
Mild — brief GH pulse
Moderate — CJC DAC sustained exposure
Moderate
S2
S2
S2
S2
Accessibility
Gray market oral; available but FDA warning actions ongoing
Gray market injectable peptide
Gray market injectable peptide combo
Gray market injectable peptides
The strategic summary: MK-677's oral route is its defining advantage. For a user who will not inject or cannot afford pharmaceutical HGH, it is the most accessible and convenient way to raise IGF-1 consistently. The tradeoffs are the 24-hour appetite stimulation (manageable with caloric discipline and evening dosing), the glucose metabolism concern (manageable with monitoring), and the modest but not dramatic body composition effects. For the user willing to inject, CJC-1295 + ipamorelin provides a more physiological pulsatile profile, lower appetite stimulation, and equivalent or better GH-axis optimization at similar cost.
MK-677 is categorically not a SARM. SARMs (Selective Androgen Receptor Modulators) bind and activate the androgen receptor. MK-677 binds the ghrelin receptor (GHSR-1a), which has no androgen receptor involvement. MK-677 does not suppress testosterone, LH, or FSH. It does not cause testicular atrophy. It does not require PCT. The conflation arises from co-marketing (vendors sell MK-677 and SARMs together) and shared gray-market regulatory status. The pharmacology is entirely different.
The most rigorous published trial (Nass 2008) showed fat-free mass gain of +1.1 kg at 12 months vs placebo in healthy older adults. Importantly: no muscle strength improvement was documented on any measure. The fat-free mass gain includes intracellular water alongside actual contractile tissue. Users expecting significant strength or muscle gains comparable to SARMs will be disappointed. MK-677's body composition effects are modest, primarily body recomposition-oriented (fat reduction; modest lean mass), and do not produce the dramatic hypertrophy community marketing implies.
MK-677 stimulates the pituitary to produce more GH through the ghrelin receptor. Exogenous HGH delivers GH directly, bypassing the pituitary entirely. They both raise IGF-1 — but via completely different mechanisms with different pharmacokinetic profiles, different selectivity, and different side effect profiles. MK-677 preserves pulsatile GH physiology and the negative feedback regulation that prevents supraphysiological IGF-1. Exogenous HGH at performance doses drives IGF-1 to potentially supraphysiological levels without the same self-limiting feedback. 'Oral HGH' framing is pharmacologically misleading.
The Merck program failures should be accurately understood: the clinical endpoint failures occurred in specific populations (elderly, often with comorbidities) using specific outcome measures (strength, functional performance, hip fracture recovery, cognitive function) over specific trial durations. The compound did raise IGF-1. It did increase fat-free mass. It did improve bone markers. The failure was specifically biomarker-to-clinical-endpoint translation in diseased/elderly populations. Whether similar biomarker-to-function dissociation occurs in younger, healthy adults using MK-677 for optimization is a different question — though the Nass 2008 data (also healthy elderly) showed the same pattern (biomarker success, no strength benefit), which is still concerning.
MK-677's regulatory status as of mid-2026 is the clearest of any compound in the GH secretagogue class: not approved, not approvable through compounding, and actively targeted by FDA enforcement. The key regulatory events: October 2024 FDA PCAC (Pharmacy Compounding Advisory Committee): specifically reviewed ibutamoren for the 503A bulk drug substance list; the committee recommended against listing — meaning licensed compounding pharmacies cannot legally compound MK-677 for patients. This closed the last potential legitimate prescription pathway in the US. December 2025 FDA warning letters: issued against SARMS AMERICA, Monster King/GE Labs, and Prime Sports Nutrition for MK-677 products sold with health claims and 'For Research Use Only' labeling. These actions follow MK-677's explicit exclusion from dietary supplement status (Section 201(ff)(3)(B)(ii) of the FD&C Act — because it was authorized for clinical investigation as a new drug before any dietary supplement claims, it cannot legally be sold as a supplement). The current legal situation: MK-677 exists in a clear regulatory gray-to-black area. It is not approved, not legally compoundable, not legally a dietary supplement, and actively targeted by FDA warning letters. It continues to be widely available through internet vendors who operate in regulatory gray areas or internationally.
Nass R, Pezzoli SS, Oliveri MC, et al. (2008). Effects of an Oral Ghrelin Mimetic on Body Composition and Clinical Outcomes in Healthy Older Adults: A Randomized, Controlled Trial. Annals of Internal Medicine. 149(9):601-611. doi:10.7326/0003-4819-149-9-200811040-00003. [n=65; 25 mg/day; 12 months; GH/IGF-1↑; FFM +1.1 kg; no strength improvement; fasting glucose +5 mg/dL; insulin sensitivity↓; the primary human evidence base for MK-677.]
Chapman IM, et al. (1996). Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects. Journal of Clinical Endocrinology and Metabolism. 81(12):4249-4257. [Dose-ranging; 10-50 mg; confirmed sustained IGF-1 elevation with once-daily oral dosing; established dose-response.]
FDA Pharmacy Compounding Advisory Committee (PCAC). October 2024. Review of ibutamoren (MK-677) for 503A bulk drug substances list. Recommendation: against listing. [Closure of last legal compounding pathway in the US; defines current regulatory status.]
FDA Warning Letters. December 2025. Issued against SARMS AMERICA, Monster King/GE Labs, Prime Sports Nutrition for ibutamoren/MK-677 products. [Most recent FDA enforcement actions; establishes ongoing FDA regulatory position.]
MK-677 is the most accessible GH-axis compound in this book. Its oral convenience is real and pharmacologically meaningful. Its body composition benefits are modest and its safety profile requires more management than most community users expect.
The honest summary: MK-677 has more published human trial data than most compounds in this book — and that data tells a specific story. IGF-1 rises reliably and persistently. Fat-free mass increases modestly (+1.1 kg over 12 months in the best trial). Glucose metabolism is impaired consistently across trials (+5 mg/dL fasting glucose at 25 mg/day). Muscle strength does not improve. The sleep quality benefit is the most consistently reported positive effect and is mechanistically sound. Appetite stimulation is significant and is the primary driver of unintended weight/fat gain in community users who don't manage caloric intake. The CHF signal in elderly patients is not relevant to young healthy adults but is relevant to older users with cardiac history. The FDA has explicitly closed the legal compounding pathway. Merck discontinued its development program after Phase 3 failures across six indications. The community continues to use it for its oral convenience and sleep/body composition optimization applications — applications where the evidence standard is more forgiving than Merck's clinical endpoints — with reasonable benefit-risk ratios if glucose is monitored, appetite is managed, and the modest body composition expectations are realistic.
— End of MK-677 (Ibutamoren) —
THE PEPTIDE BIBLE | MK-677 (Ibutamoren) | For Research & Educational Purposes Only
MK-677 (ibutamoren; ibutamoren mesylate; PubChem CID 9939050): non-peptide small molecule; GHSR-1a (ghrelin receptor) agonist; oral once-daily; half-life ~24 hours. Merck Sharp & Dohme. NOT FDA-approved. NOT a SARM (binds ghrelin receptor not androgen receptor; no testosterone/LH/FSH suppression). NOT compoundable under 503A (FDA PCAC October 2024 recommendation against listing). MECHANISM: GHSR-1a agonist at pituitary somatotrophs → GH pulse amplitude↑ and frequency↑ + somatostatin↓; hypothalamic GHSR-1a → GHRH↑, somatostatin↓; persistent 24hr receptor occupancy → sustained IGF-1 elevation + constant appetite stimulation + persistent GH-mediated glucose antagonism. Selectivity: minimal prolactin or cortisol elevation (unlike GHRP-2/GHRP-6). MERCK PROGRAM: Phase 2 and Phase 3 across 6 indications (GHD, osteoporosis, hip fracture, sarcopenia, obesity, Alzheimer's); all failed on clinical endpoints despite robust biomarker response (IGF-1↑, FFM↑); CHF signal in elderly hip fracture trial led to early termination; no NDA submitted; program discontinued. PRIMARY HUMAN TRIAL: Nass 2008 (Ann Intern Med): n=65; 25 mg/day; 12 months; GH/IGF-1↑ (to young-adult levels); FFM +1.1 kg; visceral fat↓; NO strength improvement; fasting glucose +5 mg/dL; insulin sensitivity↓. SLEEP: most consistent benefit; enhanced nocturnal GH pulse; SWS promotion; vivid dreams; improved sleep depth; evening dosing essential (1-2hrs pre-sleep). ADVERSE EFFECTS: edema (GH sodium retention; dose-dependent); appetite stimulation (significant; ghrelin mechanism; primary cause of unintended fat gain); fasting glucose elevation (consistent across trials); insulin resistance; CHF risk in elderly + cardiac compromise. ACTIVE MALIGNANCY: absolute contraindication. COMMUNITY PROTOCOL: 25 mg/day oral, evening; caloric management essential; IGF-1 monitoring every 3-4 months (target 0 to +2 SDS); glucose/HbA1c monitoring; cycle 8-12 wks on/off (convention, not evidence-based) OR continuous with monitoring. vs INJECTABLE SECRETAGOGUES: MK-677 = oral, 24hr sustained; ipamorelin = injectable, pulsatile, lower appetite; CJC+Ipa = injectable, better physiological profile; choice depends on injection tolerance. FDA 2024: PCAC against 503A inclusion. FDA December 2025 warning letters against MK-677 product vendors. WADA: S2 absolute ban; ibutamoren explicitly listed in 2025 Prohibited List. NOT HPTA suppressive. No PCT required.
A Structural Modification of Semax With No Published Studies of Its Own. Being Sold as 'The Most Potent Semax Analog.' Every Claim Belongs to Its Parent Compound.
The Compound That Raises NAD+ By Stopping the Body From Destroying It. NNMT: The Enzyme That Wastes Nicotinamide. Fat Loss Without Food Restriction in Mice. The Neelakantan Group's Research Tool Repurposed as a Longevity Drug. Zero Human Trials. 100 mg/Day Community Dose Extrapolated From Mouse IP Injections. The 1-MNA Question: The Metabolite You're Blocking Has Protective Roles in Liver and Kidney. A 2025 Cell/TPS Review Calls for Clinical Translation. Clinics Already Prescribing It Without FDA Ruling on Safety.
Six Human Clinical Trials. 900+ Participants. Safety Indistinguishable From Placebo. Primary Fat Loss Endpoint Failed. WADA Banned. FDA Rejected for Compounding. The Community Uses It Anyway at Doses That Never Worked in the Trials.