MK-677 (Ibutamoren): The Oral Growth Hormone Secretagogue Guide (2026)

MK-677, also known as ibutamoren or ibutamoren mesylate, is one of the most widely discussed compounds in the growth hormone optimization space. It sits at a unique crossroads: it is not a peptide, not a hormone, and not a steroid. It is an orally active, non-peptide compound that mimics the hunger hormone ghrelin and stimulates your body’s own growth hormone (GH) production. That oral bioavailability is what makes it unusual — most growth hormone secretagogues require injection, while MK-677 can be taken by mouth as a capsule or liquid.

But the research on MK-677 benefits goes well beyond convenience. Multiple clinical trials have investigated its effects on body composition, bone density, sleep quality, and recovery. At the same time, there are real safety considerations — particularly around blood sugar and insulin resistance — that anyone researching this compound needs to understand clearly.

This guide covers everything the current evidence tells us about MK-677: how it works, what the clinical trials actually show, how it compares to injectable GH peptides, and where the risks lie.

Table of Contents

1. What Is MK-677?
2. How MK-677 Works
3. Research-Backed MK-677 Benefits
4. MK-677 Dosage Protocols
5. Side Effects and Safety
6. MK-677 vs Injectable GH Peptides
7. MK-677 vs HGH
8. Who Should Be Cautious
9. Key Clinical Trials
10. Frequently Asked Questions
11. Key Takeaways

What Is MK-677?

MK-677 (ibutamoren mesylate) is a synthetic, orally active compound developed by Merck Research Laboratories in the mid-1990s. It is classified as a growth hormone secretagogue (GHS) — a substance that promotes the secretion of growth hormone. However, its chemical structure sets it apart from virtually every other growth hormone secretagogue on the market.

Here is the critical distinction that is often overlooked: MK-677 is not a peptide. It is a small-molecule, non-peptide compound. This matters because peptides like GHRP-6, GHRP-2, and ipamorelin are chains of amino acids that break down in the digestive tract when taken orally — which is why they must be injected. MK-677, by contrast, is a spiropiperidine compound that survives stomach acid and intestinal enzymes intact, making it one of the only growth hormone secretagogues that can be taken by mouth and still reach the bloodstream in active form.

MK-677 was specifically designed to mimic the action of ghrelin, the “hunger hormone” that your stomach produces. Ghrelin is a 28-amino-acid peptide hormone that binds to the growth hormone secretagogue receptor (GHSR1a) in the brain, primarily in the hypothalamus and pituitary gland. When ghrelin activates this receptor, it triggers a cascade that results in growth hormone release from the anterior pituitary.

MK-677 binds to the same receptor and produces the same downstream effect — GH secretion — but as a synthetic small molecule rather than a peptide. Structural studies using cryo-electron microscopy have revealed exactly how ibutamoren fits into the ghrelin receptor binding pocket, confirming its mechanism at the molecular level (Shiimura et al., 2021).

Key Characteristics of MK-677

• Chemical class: Non-peptide, spiropiperidine growth hormone secretagogue
• Route: Oral (capsule or liquid)
• Half-life: Approximately 6-8 hours, with effects on GH/IGF-1 lasting 24 hours
• Target receptor: Growth hormone secretagogue receptor type 1a (GHSR1a)
• Developer: Merck Research Laboratories
• Other names: Ibutamoren, ibutamoren mesylate, MK-0677, L-163,191
• Regulatory status: Not FDA-approved for any indication; investigational compound

One of the most appealing characteristics of MK-677 is its long duration of action. A single daily dose produces sustained elevation of GH and IGF-1 levels over a full 24-hour period, which differs from the brief, pulsatile spikes seen with injectable GH secretagogue peptides.

How MK-677 Works

Understanding MK-677’s mechanism of action requires a quick overview of how growth hormone regulation works in your body. GH secretion is controlled by two opposing signals from the hypothalamus:

1. Growth Hormone-Releasing Hormone (GHRH): Stimulates GH release from the pituitary
2. Somatostatin: Inhibits GH release

Your body produces GH in pulses, with the largest pulses occurring during deep sleep. As you age, both the amplitude and frequency of these pulses decline — a process called somatopause. By your 60s, your GH output may be a fraction of what it was at age 25.

Ghrelin Receptor Activation

MK-677 works by activating a third pathway in GH regulation: the ghrelin/GHSR1a pathway. When MK-677 binds to ghrelin receptors in the hypothalamus and pituitary, it does several things simultaneously:

1. Stimulates pulsatile GH release. Rather than creating a single flat elevation of GH (as synthetic HGH injections do), MK-677 amplifies the body’s natural pulsatile pattern. The GH pulses get larger and more frequent, but the rhythm remains physiological. This is an important distinction because pulsatile GH delivery is how your body was designed to use the hormone.

2. Increases IGF-1 production. The elevated GH signals the liver to produce more insulin-like growth factor 1 (IGF-1), the downstream mediator responsible for many of GH’s anabolic effects. IGF-1 increases are dose-dependent and sustained. In the Chapman et al. (1996) study, 25 mg/day of MK-677 raised IGF-1 into the normal young-adult range in elderly subjects (Chapman et al., 1996).

3. Does not suppress the natural GH axis. This is perhaps MK-677’s most important pharmacological feature. Unlike exogenous HGH injections, which can suppress your pituitary’s own GH production through negative feedback, MK-677 works through the body’s own secretory mechanism. The pituitary is still doing the work — MK-677 is simply telling it to work harder. Studies lasting up to two years have confirmed that GH and IGF-1 elevations are maintained without evidence of axis suppression (Nass et al., 2008).

4. May partially oppose somatostatin. There is evidence that ghrelin receptor activation can partially counteract somatostatin’s inhibitory effect on GH release, which helps explain why MK-677 can sustain elevated GH even in older individuals whose somatostatin tone is typically high.

The Appetite Connection

Because MK-677 activates the same receptor as ghrelin — the hunger hormone — it reliably increases appetite. This is not an incidental side effect. It is a direct pharmacological consequence of GHSR1a activation. The appetite stimulation tends to be most pronounced in the first few weeks of use and may attenuate somewhat over time, though it persists to some degree throughout use.

For individuals in a caloric surplus or trying to gain weight, this can be helpful. For those trying to maintain a caloric deficit, it can be a significant challenge.

Research-Backed MK-677 Benefits

The clinical trial data on MK-677 spans nearly three decades, with studies ranging from short-term dose-finding trials to a 2-year longitudinal study in elderly adults. Here is what the evidence shows for specific MK-677 benefits.

1. Increased Growth Hormone and IGF-1 Levels

This is the most robustly documented effect. Every published clinical trial on MK-677 has demonstrated significant increases in GH and IGF-1.

In healthy elderly subjects (ages 64-81):

• 25 mg/day for 14 days increased mean 24-hour GH concentrations by 97% compared to baseline (Chapman et al., 1996)
• IGF-1 levels increased to within the normal range for healthy young adults
• Over 12 months of use, GH levels increased 1.8-fold from baseline, and serum IGF-1 levels increased approximately 1.5-fold (Nass et al., 2008)

In healthy young men:

• 25 mg/day for 7 days increased mean 24-hour GH concentration and GH peak amplitudes without altering GH pulse frequency (Copinschi et al., 1996)
• The GH increase maintained the normal pulsatile pattern rather than creating continuous elevation

In GH-deficient adults:

• 10 mg MK-677 increased IGF-1 by 52% and 24-hour mean GH by 79%
• 50 mg MK-677 increased IGF-1 by 79% and 24-hour mean GH by 82% (Bach et al., 1997)

In obese subjects:

• 25 mg/day for 8 weeks increased GH secretion, with IGF-1 levels rising significantly from baseline (Svensson et al., 1998)

The consistency of these findings across different populations — young, elderly, obese, GH-deficient — is notable. MK-677 reliably elevates the GH-IGF-1 axis regardless of the starting population.

2. Lean Body Mass and Body Composition

The body composition data is encouraging but comes with an important caveat.

Nass et al. (2008) — The 2-Year Elderly Study:
In this landmark trial of 65 healthy adults aged 60-81, MK-677 at 25 mg/day for 12 months produced the following results:

• Fat-free mass increased by 1.1 kg in the MK-677 group, while the placebo group lost 0.5 kg of fat-free mass
• Body cell mass (measured by intracellular water) increased by 0.8 kg with MK-677 versus a decrease of 0.5 kg with placebo
• Total body fat and visceral fat were not significantly changed

Svensson et al. (1998) — Obese Males Study:
In 24 healthy obese males treated for 8 weeks:

• Fat-free mass increased by approximately 3 kg compared to placebo (P < 0.01)
• Body cell mass increased by approximately 1 kg (P < 0.05)
• Total and visceral fat were not significantly changed

The caveat: In the Nass study, the increase in fat-free mass did not translate to improvements in strength or physical function. Some researchers have noted that a portion of the “lean mass” increase may reflect intracellular water retention rather than new contractile muscle tissue. This does not invalidate the finding — increased cell hydration has its own physiological significance — but it tempers expectations for those hoping for dramatic muscle growth from MK-677 alone.

3. Bone Density and Bone Turnover

MK-677 has shown promising effects on bone metabolism, though the picture is complex and appears to depend on treatment duration.

Svensson et al. (1998) — Bone Markers in Obese Males:
In this 8-week study, MK-677 at 25 mg/day significantly increased markers of bone formation:

• Carboxy-terminal propeptide of type I procollagen (a bone formation marker) increased 23% within 2 weeks
• Procollagen III peptide levels increased 28%
• Osteocalcin (another bone formation marker) also increased significantly (Svensson et al., 1998)

Murphy et al. (2001) — Postmenopausal Osteoporosis Study:
In postmenopausal women with osteoporosis, MK-677 combined with alendronate (a bisphosphonate) was studied over 18 months:

• MK-677 plus alendronate increased bone mineral density (BMD) at the femoral neck by 4.2%, compared to 2.5% with alendronate alone (P < 0.05)
• However, there was no significant additional benefit at the lumbar spine, total hip, or total body (Murphy et al., 2001)

The bone data suggests that MK-677 increases bone turnover — both formation and resorption — with a net effect that may favor bone building at certain skeletal sites and over certain time frames.

4. Sleep Quality Improvement

The sleep data on MK-677 is among its most compelling and clinically relevant findings.

Copinschi et al. (1997) — The Sleep Study:
In a study of young and elderly subjects receiving MK-677 at 25 mg/day, polysomnographic measurements revealed significant improvements in sleep architecture:

• Duration of stage IV (deep/slow-wave) sleep increased by approximately 50%
• REM sleep duration increased by more than 20%
• The number of deviations from normal sleep decreased significantly
• Sleep quality improvements occurred in both young and older subjects (Copinschi et al., 1997)

These are substantial improvements. Stage IV sleep is the most physically restorative phase of the sleep cycle — it is when GH secretion naturally peaks, when tissue repair is most active, and when memory consolidation occurs. REM sleep is critical for cognitive function, emotional regulation, and overall brain health.

For many researchers and practitioners, the sleep improvement is considered one of the most practical and immediately noticeable MK-677 benefits, with users frequently reporting deeper sleep and more vivid dreams within the first week of use.

5. Nitrogen Retention and Anti-Catabolic Effects

Murphy et al. (1998) — Diet-Induced Catabolism Study:
In a double-blind, placebo-controlled crossover study, eight healthy volunteers were placed on a calorie-restricted diet (18 kcal/kg/day) for two 14-day periods. MK-677 was shown to:

• Reverse nitrogen wasting caused by caloric restriction
• Improve nitrogen balance, suggesting preservation of lean tissue during dieting
• Produce these anti-catabolic effects through increased GH-mediated protein synthesis (Murphy et al., 1998)

This finding has significant implications for individuals in caloric deficit — whether athletes cutting weight, post-surgical patients, or elderly individuals experiencing involuntary weight loss.

MK-677 Dosage Protocols

The clinical trial literature provides clear guidance on the dosages that have been studied. It is important to note that MK-677 is not FDA-approved, and no official dosing guidelines exist. The following information reflects research dosing protocols used in published studies.

Commonly Studied Doses

Dosing Observations from Research

25 mg appears to be the most widely studied and effective dose. The majority of clinical trials used 25 mg/day, and this dose consistently produced robust elevations in GH and IGF-1 without a proportionally higher side effect burden compared to lower doses.

10 mg/day may offer a more conservative approach with meaningful GH elevation and potentially fewer side effects related to appetite stimulation and blood glucose impact.

Timing: Most studies administered MK-677 once daily. Given its approximately 6-8 hour half-life but 24-hour effect on IGF-1 levels, once-daily dosing appears sufficient. Many practitioners recommend evening administration to capitalize on the synergy between MK-677’s GH-boosting effects and the natural nocturnal GH surge, as well as to potentially leverage its sleep-improving properties.

Cycling considerations: The Nass et al. (2008) study administered MK-677 continuously for up to 2 years with maintained efficacy, suggesting that tolerance (tachyphylaxis) does not appear to develop for the GH-IGF-1 elevating effects. However, some practitioners recommend cycling protocols (such as 8 weeks on, 4 weeks off, or 5 days on, 2 days off) to manage side effects like appetite stimulation and blood glucose elevation.

Duration: Clinical trials have ranged from 7 days to 2 years. The GH and IGF-1 effects appear within the first week and are sustained throughout treatment. Body composition and bone turnover effects become more apparent after 8-12 weeks of consistent use.

Side Effects and Safety

MK-677’s side effect profile is well-characterized thanks to multiple clinical trials with careful monitoring. Some effects are direct consequences of its pharmacology (ghrelin receptor activation and GH elevation), while others warrant careful attention.

1. Increased Appetite

This is the most predictable and consistent side effect. Because MK-677 activates the ghrelin receptor — the same receptor activated by the hunger hormone — increased appetite is essentially guaranteed. The effect tends to be most pronounced during the first 2-4 weeks and may moderate somewhat with continued use, though it does not disappear entirely.

2. Blood Sugar and Insulin Resistance — The Major Safety Concern

This is the single most important safety consideration with MK-677, and it deserves detailed attention.

Growth hormone is a counter-regulatory hormone to insulin. When GH levels rise, blood glucose tends to rise as well, because GH promotes glucose production in the liver and reduces glucose uptake by muscle and fat tissue.

The clinical trial data is clear on this point:

• In the Chapman et al. (1996) study, MK-677 at 25 mg/day increased fasting glucose concentrations by 25.3% at 2 weeks and 26.9% at 4 weeks above baseline (Chapman et al., 1996)
• In the Nass et al. (2008) 2-year study, fasting blood glucose increased with MK-677 but not with placebo. HbA1c also showed increases, and some subjects who were already prediabetic at baseline progressed to meet diabetes criteria (Nass et al., 2008)
• Insulin levels rise in parallel with glucose, reflecting an insulin-resistant state

This effect is dose-dependent and appears to persist throughout treatment. For anyone with pre-existing insulin resistance, prediabetes, metabolic syndrome, or type 2 diabetes, MK-677 can meaningfully worsen glycemic control.

3. Water Retention and Edema

Mild to moderate fluid retention is common with MK-677, particularly during the first few weeks. This manifests as temporary increase in body weight (water, not fat), mild puffiness in hands, feet, or face, and a feeling of fullness in the extremities. It tends to stabilize after 2-4 weeks.

4. Numbness and Tingling (Paresthesia)

Some individuals report transient numbness or tingling in the hands, particularly upon waking. This is likely related to fluid retention causing mild compression of nerves. It is generally mild and resolves with time or dose reduction.

5. Transient Lethargy

Some users report increased tiredness or lethargy, particularly in the first 1-2 weeks. This may be partially related to the sleep architecture changes and partially to the metabolic adjustments occurring as GH and IGF-1 levels shift.

6. Joint Pain

Mild joint discomfort has been reported in some clinical trial subjects, consistent with the joint-related side effects seen with GH therapy. This appears to be dose-dependent and is more common at higher doses.

7. Cortisol Effects

MK-677 has been shown to produce modest, transient increases in cortisol levels, particularly in the short term. In the Copinschi et al. (1996) study, cortisol levels increased during the first week but the effect was not sustained with continued administration. Most researchers consider this effect clinically insignificant given its transient nature.

MK-677 vs Injectable GH Peptides

One of the most common questions is how MK-677 compares to injectable growth hormone secretagogue peptides like CJC-1295, ipamorelin, GHRP-6, and sermorelin.

MK-677 vs CJC-1295/Ipamorelin

Key distinction: CJC-1295 and ipamorelin work through the GHRH pathway and provide a more “selective” GH stimulus with less appetite stimulation and potentially less glucose impact. MK-677 provides broader ghrelin receptor activation that includes appetite stimulation and possibly greater effects on sleep. Many practitioners view these as complementary pathways rather than direct substitutes.

MK-677 vs GHRP-6

GHRP-6 (Growth Hormone-Releasing Peptide 6) is an injectable peptide that, like MK-677, acts on the ghrelin receptor. Both compounds produce significant appetite stimulation through this shared mechanism. However, GHRP-6 has a much shorter half-life (approximately 15-60 minutes) and requires multiple daily injections. MK-677’s oral bioavailability and longer duration of action make it considerably more convenient for the same general mechanism of action.

MK-677 vs Sermorelin

Sermorelin is a 29-amino-acid peptide that is a truncated analog of GHRH. It works exclusively through the GHRH pathway and does not activate ghrelin receptors. Sermorelin tends to produce a more physiological, modest GH elevation with a cleaner side effect profile — no appetite stimulation, minimal glucose impact. However, it requires daily injection and produces smaller absolute increases in GH and IGF-1 compared to MK-677 at standard doses.

MK-677 vs HGH (Synthetic Human Growth Hormone)

The trade-off is clear: HGH gives you precise control and potentially greater GH/IGF-1 elevation, but at dramatically higher cost, with injection requirements, and with the risk of suppressing your pituitary’s own GH production. MK-677 is cheaper, oral, and works with your body’s own machinery, but provides less precise control, reliably stimulates appetite, and consistently affects blood glucose.

Neither approach is universally superior. The choice depends on the specific goals, health status, and risk tolerance of the individual — decisions that should be made with a qualified healthcare provider.

Who Should Be Cautious

Based on the available clinical evidence, certain populations should exercise particular caution or avoid MK-677 altogether.

Diabetes and Pre-Diabetes

Given MK-677’s consistent effect on fasting glucose and insulin sensitivity, individuals with type 2 diabetes, prediabetes (fasting glucose 100-125 mg/dL or HbA1c 5.7-6.4%), or strong risk factors for diabetes should be especially careful. The Nass et al. (2008) study noted that some subjects with borderline glucose at baseline progressed to diabetic thresholds during MK-677 treatment.

Insulin Resistance and Metabolic Syndrome

Even without a diabetes diagnosis, individuals with insulin resistance (elevated fasting insulin, elevated HOMA-IR) may see their metabolic profile worsen with MK-677. Regular glucose and insulin monitoring would be essential.

Cancer History

GH and IGF-1 are growth-promoting hormones. While MK-677 has not been shown to cause cancer in clinical trials, elevating growth factors in someone with an active malignancy or recent cancer history is generally considered inadvisable by most oncologists. This caution applies to all forms of GH therapy, not just MK-677.

Heart Failure and Edema

The fluid retention effects of MK-677, while mild in healthy individuals, could be problematic for those with congestive heart failure or conditions where fluid management is critical.

Children, Adolescents, Pregnancy

MK-677 has not been adequately studied in pediatric populations for safety. No safety data exists for pregnancy or lactation. It should not be used by these populations.

Key Clinical Trials

The following trials represent the core of the clinical evidence base for MK-677.

Chapman et al. (1996) — GH-IGF-1 Axis in Elderly Subjects

• Design: Randomized, double-blind, placebo-controlled
• Subjects: 32 healthy elderly adults (ages 64-81)
• Doses: Placebo, 2 mg, 10 mg, or 25 mg daily
• Duration: Two periods of 14 and 28 days
• Key findings: 25 mg/day increased mean 24-hour GH by 97% and raised IGF-1 to young-adult reference ranges. Fasting glucose increased 25-27% above baseline at 25 mg.
• Reference: Chapman et al., 1996

Copinschi et al. (1996) — 24-Hour GH Profiles in Young Men

• Design: Randomized, double-blind, three-period crossover
• Subjects: 9 healthy young men
• Doses: Placebo, 5 mg, or 25 mg daily for 7 days per period
• Key findings: 25 mg/day increased GH peak amplitude without altering pulse frequency. Transient cortisol increase observed.
• Reference: Copinschi et al., 1996

Copinschi et al. (1997) — Sleep Quality Study

• Key findings: Stage IV (deep) sleep duration increased approximately 50%. REM sleep increased by more than 20%.
• Reference: Copinschi et al., 1997

Bach et al. (1997) — GH-Deficient Adults

• Key findings: 10 mg increased IGF-1 by 52% and GH by 79%. 50 mg increased IGF-1 by 79% and GH by 82%.
• Reference: Bach et al., 1997

Murphy et al. (1998) — Diet-Induced Catabolism

• Key findings: MK-677 reversed diet-induced nitrogen wasting, preserving lean tissue during caloric deficit.
• Reference: Murphy et al., 1998

Svensson et al. (1998) — Body Composition in Obese Males

• Key findings: Fat-free mass increased approximately 3 kg (P < 0.01). Bone formation markers increased 23-28%.
• Reference: Svensson et al., 1998

Murphy et al. (2001) — Postmenopausal Osteoporosis

• Key findings: MK-677 plus alendronate increased femoral neck BMD by 4.2% vs. 2.5% with alendronate alone.
• Reference: Murphy et al., 2001

Nass et al. (2008) — The Landmark 2-Year Elderly Study

• Subjects: 65 healthy adults (ages 60-81)
• Duration: 2 years
• Key findings: GH increased 1.8-fold. IGF-1 increased 1.5-fold. Fat-free mass increased 1.1 kg. No improvement in strength. Fasting glucose and HbA1c increased. Effects sustained without tachyphylaxis.
• Reference: Nass et al., 2008

Sevigny et al. (2008) — Alzheimer’s Disease Trial

• Subjects: 563 patients with mild to moderate Alzheimer’s disease
• Key findings: Despite IGF-1 increasing 60-73%, there were no significant changes in any clinical outcome measure for Alzheimer’s progression.
• Reference: Sevigny et al., 2008

Frequently Asked Questions

Is MK-677 a peptide?

No. MK-677 is frequently discussed alongside peptides because it acts on the same biological pathways, but it is chemically a non-peptide, small-molecule compound — specifically a spiropiperidine derivative. This is precisely why it can be taken orally: peptides are chains of amino acids that would be broken down by digestive enzymes, but MK-677’s non-peptide structure survives the GI tract intact.

How quickly does MK-677 start working?

GH and IGF-1 elevations are measurable within the first dose and become significant within the first week. Sleep improvements are often subjectively noticeable within 1-2 weeks. Body composition changes (lean mass increases) require 8-12 weeks of consistent use to become apparent, based on clinical trial timelines.

Does MK-677 suppress natural growth hormone production?

No. Unlike exogenous HGH injections, MK-677 works by stimulating the pituitary gland to produce and release its own GH through the ghrelin receptor pathway. Studies lasting up to 2 years have not shown evidence of pituitary suppression or tachyphylaxis (loss of efficacy over time).

Can MK-677 cause diabetes?

MK-677 does not directly cause diabetes, but it reliably increases fasting blood glucose and reduces insulin sensitivity. In the Nass et al. (2008) study, some subjects with borderline glucose at baseline progressed to diabetic thresholds during treatment. Anyone with pre-existing insulin resistance, prediabetes, or metabolic syndrome is at meaningfully higher risk of adverse glycemic effects.

Should MK-677 be taken in the morning or at night?

Most clinical trials administered MK-677 once daily without specifying timing. However, many practitioners recommend evening administration to align with the body’s natural nocturnal GH surge and to take advantage of MK-677’s demonstrated sleep quality improvements. Taking it at night may also help manage the appetite stimulation, as the increased hunger signal occurs during sleep.

Does MK-677 need to be cycled?

The clinical evidence does not show tolerance developing over periods up to 2 years, so cycling is not strictly necessary from an efficacy standpoint. However, some practitioners recommend cycling to give the body periodic breaks from the glucose and insulin effects. Common cycling approaches include 5 days on/2 days off, or 8-12 weeks on with 4-week breaks.

Can MK-677 be stacked with other peptides?

MK-677 is commonly discussed in combination with other GH-related compounds. Because it works through the ghrelin receptor while compounds like CJC-1295 work through the GHRH receptor, they act through complementary pathways. However, stacking multiple GH secretagogues amplifies side effects — particularly glucose and insulin impact — and requires careful metabolic monitoring. Any combination protocols should be discussed with a qualified healthcare provider.

Is MK-677 legal?

The legal status of MK-677 varies by jurisdiction. In the United States, MK-677 is not a scheduled controlled substance and can be purchased as a research chemical. However, it is not FDA-approved for any human use and cannot be legally marketed as a dietary supplement or drug. It is banned by the World Anti-Doping Agency (WADA) and prohibited in virtually all competitive sports. Always verify current regulations in your specific location.

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References

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7. Svensson J, Ohlsson C, Jansson JO, et al. Treatment with the oral GH secretagogue MK-677 increases markers of bone formation and bone resorption in obese young males. J Bone Miner Res. 1998;13(7):1158-1166. PubMed
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