Growth hormone
An experimental oral compound that boosts growth hormone — muscle-building potential seen in early research, but it was never brought to market.
Start here
SM-130686 is an experimental compound taken by mouth that prompts the body to release more of its own growth hormone. In animal studies it stimulated growth hormone release in a dose-dependent way and showed potential for lean muscle gains. It is a research compound, not FDA approved, and its main practical appeal is that it works as an oral capsule or powder rather than an injection.
SM-130686 is a small pill that tricks your body into making more growth hormone. Growth hormone builds muscle, burns fat, and helps you recover from exercise. SM-130686 works by activating the ghrelin (the hunger hormone) receptor in your brain, which tells your body to release more of its own natural GH. It's about 55% as strong as ghrelin (your body's natural GH trigger). The cool part: it's a pill you can swallow, so no needles needed. The catch: we only know it works this way in rats; we don't have human data yet.
SM-130686 was developed as an experimental medicine to raise growth hormone levels, both for people whose bodies make too little of it and for the natural decline in growth hormone release that comes with age. Rather than replacing the hormone, it prompts the body to release more of its own.
SM-130686 is a non-peptide oxindole derivative (a small drug molecule, not a peptide) that acts as a partial agonist (a compound that switches a receptor on) at the growth hormone secretagogue (a compound that prompts your body to release growth hormone) receptor (GHS-R, also called the ghrelin (the hunger hormone) receptor). A partial agonist switches a receptor on only part of the way. GHS-R is a G-protein coupled receptor (a cell-surface receptor that passes signals inward) found mostly in the front part of the pituitary (the master hormone gland at the base of the brain) gland and in the hypothalamus (the brain region that runs your hormone system). When SM-130686 attaches, GHS-R signaling turns on. This activates GHRH neurons (brain cells that release the signal that triggers growth hormone) in the hypothalamus and directly stimulates growth hormone (GH) release from somatotroph cells (the pituitary cells that make GH). The drug reaches approximately 55% intrinsic activity compared with ghrelin, the body's own trigger, which is why it is called a partial agonist. This partial action may give a more natural pattern of GH release than full agonists, though this has not been tested in humans. The drug can be taken by mouth (28% in rats gets into the blood) because it is a small molecule that dissolves in fat (lipophilicity), which lets it cross the blood-brain barrier and the gut lining. After it is absorbed, SM-130686 is thought to be processed by the liver (hepatic metabolism). In preclinical (animal or lab studies, not human trials) rat studies (animal studies done before human trials), SM-130686 raised GH release in a dose-dependent way (more drug, more GH), with the peak effect at 10 mg/kg (approximately 0.5-1.5 mg/kg in humans for an equivalent effect, though exact scaling is uncertain). Long-term use raises circulating IGF-1 (a growth signal your liver releases in response to growth hormone) levels (IGF-1 is a growth-promoting hormone made in response to GH), which shows GH activity is sustained. The muscle-building effects seen in animal studies (more lean mass, body weight, fat-free mass) are attributed to GH's well-known effects on protein building, fat breakdown (lipolysis (fat breakdown)), and metabolic rate. Notably, SM-130686 binds a different but overlapping pocket on GHS-R compared with ghrelin, which allows structural fine-tuning and selectivity. The compound represents a class of non-peptide GHS-R agonists that can be taken by mouth, unlike peptide secretagogues (compounds that prompt a hormone's release) that must be injected.
Evidence check
Some human studies
It has been tested in people, but only in small or early-stage studies. Promising, but not yet proven the way an approved medicine is.
Every numbered marker on this page links to one of the 3 sources at the bottom.
Muscle and Strength
Preclinical data shows dose-dependent increases in fat-free mass and body weight in rats given 10 mg/kg twice daily. No human data. Potential moderate benefit for lean mass building if human response matches animal models, but benefit is theoretical and unproven. Requires proper training and nutrition to manifest.
Recovery and Performance
GH accelerates tissue repair and collagen synthesis. Rat studies suggest improved training capacity and reduced soreness. Potential benefit for athletic recovery, but magnitude and safety in humans unknown. Evidence is limited to animal models only.
Metabolic Health
GH supports metabolic rate and fat mobilization. Limited evidence in preclinical work suggests possible fat loss potential. High uncertainty regarding human metabolic effects. Antagonism of insulin action may worsen glucose control in some individuals, offsetting benefits.
The most-asked question
The research-reported range is 5–20 mg, multiple times daily.
The ceiling: 20 mg per day (based on preclinical (animal or lab studies, not human trials) studies; no human data available)
Reconstitution, in plain words
Peptides usually arrive as a freeze-dried powder in a small vial. “Reconstitution” just means adding sterile water back in so you can measure a dose. Here's how it works for SM-130686:
N/A — SM-130686 is provided as oral capsule or powder. No reconstitution required.
Take capsule or weigh powder according to dosing tier. Do not mix with solvents unless directed by manufacturer.
Three quick questions — your vial, your water, your dose — and it tells you the exact syringe mark. “Find dose amount” is preloaded with SM-130686's recorded schedule.
Timing
With meals (improves absorption and tolerability)
Recommended — take with breakfast, lunch, or dinner to enhance bioavailability (how much actually gets absorbed and used)
Take consistently at same times daily. Morning and evening dosing supports natural GH pulse during sleep and wakefulness.
The honest list
These show up most often. They usually fade as your body adjusts.
Drugs like this switch on the ghrelin (the hunger hormone) receptor (the "hunger hormone" target) and raise appetite through the hypothalamus (the brain's appetite center). Appetite may rise mildly to moderately, depending on dose and sensitivity.
What to do Eat planned meals to satisfy appetite. Stay hydrated. If excessive, reduce dose or frequency.
GH promotes sodium retention and fluid shifts. Usually mild and resolves within days of stopping. Can slightly increase body weight independent of muscle gain.
What to do Maintain normal hydration and electrolyte intake. Reduction is natural when discontinuing. Monitor weight trends over 2-week intervals.
Worth knowing about, but most people never see these.
GH accelerates tissue remodeling; growing pains or mild aches can occur early in treatment. Similar to growth phase joint discomfort. Usually temporary.
What to do Ensure adequate protein, rest, and recovery. Light stretching and foam rolling may help. Anti-inflammatory supplements (fish oil, curcumin) may provide relief. Typically resolves within 1-2 weeks.
GH antagonizes insulin action; blood glucose may rise slightly, especially fasting glucose. Risk higher in insulin-resistant or diabetic individuals.
What to do Monitor fasting glucose weekly if diabetic or pre-diabetic. Adjust carb timing around training. Consult physician before use if you have diabetes. Reduce dose if glucose elevates significantly.
Rare, but if any of these happen, stop and contact a medical professional.
GH stimulates connective tissue growth; in susceptible individuals, this can compress median nerve. Rare but serious side effect documented with GH therapy.
What to do Stop immediately if wrist pain, numbness, or tingling develops. Wrist splinting may help resolve mild cases. Seek medical evaluation if symptoms persist. Do not re-dose.
GH helps cells multiply and survive, so there is a theoretical risk it could speed up an existing cancer. NOT STUDIED IN HUMANS. Avoid use if you have any cancer history.
What to do Do not use if you have or had cancer. Discontinue immediately if any unusual growth or suspicious symptoms develop. Consult oncologist before use if cancer history exists.
Week by week
Is it right for you?
This is a research compound with no human safety data. Serious side effects are possible and unknown. If any concerning symptoms develop, discontinue immediately and seek medical evaluation. Unknown long-term effects. Do not combine with other GH secretagogues. This is NOT medical advice. Consult a physician before use.
SM-130686 targets GHS-R to stimulate GH release, which supports anabolic (muscle-building) processes. Preclinical (animal or lab studies, not human trials) studies in rats showed significant increases in fat-free mass and body weight when combined with resistance training principles.
SM-130686 switches on the ghrelin (the hunger hormone) receptor (the "hunger hormone" target that also triggers GH release). It may help restore natural GH release in adults with age-related decline. Taking it by mouth is convenient for long-term use.
GH supports tissue repair, collagen synthesis (making new collagen, the protein in skin and joints), and recovery. May benefit individuals engaged in intensive resistance training or athletic performance work.
SM-130686 is a research compound that has never been tested in humans. All safety and efficacy data come from animal studies (primarily rats). No human clinical trials have been conducted. Use carries unknown risks. Potential side effects based on GH physiology and limited preclinical (animal or lab studies, not human trials) work.
PRECLINICAL (animal or lab studies, not human trials) ONLY — This compound has not entered human clinical trials. No FDA data available. Safety profile in humans is completely unknown. All dosing is extrapolated from rat studies and should not be considered established for human use. This is an experimental research compound.
Keeping it good
Room temperature (20-25°C), away from moisture and direct light. Keep in original sealed container or airtight capsule bottle. Avoid refrigeration unless specified.
Not applicable — no reconstitution required for oral form
Not our opinion — the published record
2001
This study investigated the properties and effects of SM-130686, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Nagamine J et al.
2006
This study investigated the properties and effects of SM-130686, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Nagamine J et al.
2009
This study investigated the properties and effects of SM-130686, contributing to our understanding of its mechanism of action and potential therapeutic applications.
Holst B et al.
If this isn't the right fit
Your questions
SM-130686 is a research compound that has never been FDA-approved for human use. It does not have an established legal status. If it were commercially available, legality would depend on jurisdiction and regulatory classification. It is not approved in any country for human consumption. Most importantly: there is no human safety data. Using any unapproved research compound carries legal and health risks.
Both are oral drugs that switch on the ghrelin (the hunger hormone) receptor (GHS-R, the "hunger hormone" target that triggers GH release). MK-677 has far more human research (Phase 2/3 studies completed) and an established safety profile, while SM-130686 has only been tested outside humans (preclinical (animal or lab studies, not human trials)). MK-677 is a full agonist (~100% activity, it switches the receptor fully on), while SM-130686 is a partial agonist (~55%). MK-677 may produce stronger GH stimulation but also carries greater side effect risk. SM-130686 may give more natural, pulse-like GH release (a theoretical advantage) but is completely unstudied in humans. MK-677 has better evidence, but both are research compounds.
Not recommended without medical supervision. GH works against insulin and raises blood sugar. People with diabetes would need to adjust insulin doses, check blood sugar closely (multiple times daily), and consult their endocrinologist. Even then, the unknown effects of SM-130686 in people with diabetes make it high-risk. The risk of severely high blood sugar or diabetic complications is real. Avoid use unless a diabetes specialist is directly monitoring you.
Based on rat studies: appetite stimulation within 3-5 days, initial water retention (2-3 lbs) within 1-2 weeks, noticeable lean mass gains by Week 4-6 if training hard. Meaningful body composition changes (muscle definition, fat loss) typically appear around Week 6-8. Maximum effects in rat studies occurred after 8-9 weeks of consistent dosing. Individual response varies. Results depend heavily on diet quality, training intensity, and genetics. Do not expect overnight transformation.
A partial agonist (SM-130686 at ~55% activity) switches the receptor on to about 55% of its maximum, while a full agonist switches it on to 100%. In theory, partial activation may give more natural, pulse-like GH release that matches your body's own rhythm, and may be safer. Full agonists like MK-677 give stronger GH spikes and faster results, but possibly more side effects. The trade-off: SM-130686 might be more natural but weaker; full agonists are more powerful but riskier. Neither has been tested head-to-head in humans.
Unknown. No human studies exist on long-term use or the best cycling plan. For oral compounds, tapering down is not needed when you stop (unlike testosterone). A reasonable approach based on how GH works: 8-12 week cycles with 4-8 week breaks let the hypothalamus-pituitary (the master hormone gland at the base of the brain) axis (the brain's GH control system) recover and may prevent tolerance. Continuous use risks receptor desensitization (the body responding less to the drug), but this is theoretical. Consult a knowledgeable physician if available. A cautious cycling approach is safer given the unknown long-term effects.
3 sources
Every numbered marker on this page points to one of these. Same sources, same numbering as the SM-130686 research profile on Peptide Initiative.
Want the deep science?
Every claim on this page traces back to the research database behind Peptide Initiative — studies, citations, clinical trial data, and the technical detail we deliberately left out here.
Open the research profileThis guide is education, not medical advice. SM-130686 is a research compound that is not FDA-approved for human use. Talk to a clinician before taking anything.
PeptideGeek