Ibutamoren Mesylate (MK-677) stimulates growth hormones to aid muscle growth. However, studies have found other interesting uses & side effects. Read on to find out what these potential benefits are, whether ibutamoren can help you, and how to deal with potential side effects.

Disclaimer: By writing this post, we are not recommending this drug. Some of our readers who were already taking the drug requested that we commission a post on it, and we are simply providing information that is available in the clinical and scientific literature.

What is Ibutamoren?

Growth Hormone Stimulator

Ibutamoren is frequently discussed on online forums for its muscle-building properties. It is available over the counter (OTC) and used by those wishing to increase their growth hormone levels.

However, clinical studies of this compound are few. Below we will highlight the current knowledge about ibutamoren.

Ibutamoren (also known as ibutamoren mesylate or MK-677), promotes the secretion of the growth hormone (GH) and increases insulin-like growth factor 1 (IGF-1) [1, 2].

Ibutamoren increases growth hormone levels by mimicking the action of the hormone ghrelin and binding to one of the ghrelin receptors (GHSR) in the brain. Activated GHSR stimulates growth hormone release from the brain.

GHSR is found in brain regions that control appetite, pleasure, mood, biological rhythms, memory, and cognition [3].

Therefore, we can expect that ibutamoren may also affect these functions. However, so far, clinical studies describe only the effects ibutamoren has on appetite – and as expected, like ghrelin, ibutamoren increases it.

A great thing about ibutamoren is that it increases growth hormone levels with little or no increase in other hormones, such as cortisol. Cortisol suppresses the immune system, reduces wound healing, and impairs learning and memory, and it’s usually not good to have this hormone elevated [4, 5].

Ibutamoren is an OTC drug that raises growth hormone and IGF-1. It has no impact on other hormones such as cortisol.



  • Boosts growth hormone
  • Increases lean body mass
  • Enhances fat burning
  • Strengthens the bones
  • Improves sleep quality
  • May support cognition and longevity


  • May cause swelling and muscle pain
  • May increase blood sugar and cause insulin resistance
  • May raise blood pressure and cause heart failure
  • Dangerous for cancer patients

Potential Uses of Ibutamoren

1) Builds Muscle

Ibutamoren is frequently used as an anabolic substance, to increase lean body mass i.e. create bigger muscles. It is orally active and can be taken once a day. These are all benefits compared to other growth hormone stimulators.

As previously mentioned, ibutamoren increases growth hormone levels and IGF-1 [1, 2]. Both growth hormone and IGF-1, in turn, increase muscle mass, muscle strength, and reduce body fat [6, 7].

In 24 obese men, a two-month treatment with ibutamoren increased lean mass, and transiently increased basal metabolic rate (BMR) [8].

By boosting growth hormone and IGF-1, ibutamoren may increase muscle mass and reduce body fat. It’s popular among bodybuilders and can be taken orally.

2) Prevents Muscle Wasting

In a study of eight food-deprived healthy volunteers, ibutamoren reversed protein loss, that could cause muscle wasting [9].

In 123 elderly patients with hip fracture, ibutamoren improved gait speed, muscle strength and reduced the number of falls [10].

3) Increases Bone Density

Growth hormone (GH) increases bone turnover and eventually bone density. However, because of the increased turnover in subjects treated with growth hormone, bone density can initially drop before increasing [211].

Basically, it takes time (> 1 year) to see the bone density increase.

In 24 healthy obese male volunteers, ibutamoren increased bone turnover [12].

In three clinical trials of 187 elderly adults (65+ years), ibutamoren increased bone building, as measured by osteocalcin, a marker of bone turnover [11].

In one study with 292 postmenopausal women, ibutamoren increased bone mineral density, which helps increase bone strength and prevent osteoporosis [13].

Ibutamoren improves bone mineral density in the long run, though it may initially lower it due to increased bone turnover.

4) Improves Sleep Quality

A study showed that in both younger and elderly subjects, ibutamoren improved sleep quality and REM (rapid eye movement) sleep duration [14].

Apart from scientific studies, there have been many reports of improved sleep quality across online forums.

5) May Promote Longevity

Growth Hormone (GH) secretion and muscle mass both decline from mid-puberty throughout life [2].

In a study with 65 older adults, daily ibutamoren increased GH and IGF-1 levels to those of healthy young adults without serious adverse effects [2].

IGF-1 is known to have beneficial effects on longevity [15, 16].

In another study with 24 obese males (double-blind randomized controlled trial), ibutamoren rejuvenated the growth hormone profile [8].

Ibutamoren may promote longevity by increasing growth hormone and IGF-1.

6) Nootropic Effects

Some people use ibutamoren as a nootropic because it acts on the ghrelin receptor, which has nootropic effects. You can read more about these effects in the post on ghrelin. Science is, however, yet to determine if and how ibutamoren affects cognitive performance.

Two indirect mechanisms by which ibutamoren may improve brain function include:

  • Increasing IGF-1, which improves memory and learning [1718]
  • Boosting REM sleep duration and sleep quality, which is essential for cognitive function [19, 14]

A study questioned the association of low IGF-1 and Alzheimer’s disease, and whether ibutamoren could help. However, in this study, ibutamoren was ineffective at slowing the progression of Alzheimer’s in humans [20].

Some users claim ibutamoren has nootropic effects. It might boost cognition by improving sleep quality and increasing IGF-1, but clinical trials haven’t confirmed this yet.

7) Combats Growth Hormone Deficiency

Ibutamoren can increase growth hormone, IGF-1, and IGFBP-3 levels in children with growth hormone deficiency without changing the concentrations of prolactin, glucose, triiodothyronine (T3), thyroxine (T4), thyrotropin, cortisol or insulin [21].

It had a similar effect on severely GH-deficient men, but insulin and glucose increased, too [22].

8) May Support Wound Healing and Tissue Regeneration

Growth hormone increases tissue regeneration and wound healing, so ibutamoren might help with these [23, 24].

There are individual reports of ibutamoren being helpful, but scientific studies are lacking.

9) Hangovers

This one is anecdotal, but people report curing hangovers with ibutamoren.

Ibutamoren helps reverse growth hormone deficiency. According to user experiences, it might also support wound healing and cure hangovers.

Side Effects of Ibutamoren

The most frequent side effects of ibutamoren are increased appetite, mild lower extremity edema, and muscle pain [2].

Several studies report an increase in fasting blood glucose and a decrease in insulin sensitivity [2, 22].

These side effects are similar to those observed in people with elevated growth hormone levels, mainly joint pain and insulin resistance [25, 26].

Although most studies report little or no side effects, one study was terminated because of serious adverse events.

In elderly patients with hip fracture, ibutamoren elevated blood pressure, blood glucose and HbA1c, and there were cases of congestive heart failure. The patients who experienced congestive heart failure were over 80 and had a history of prior heart failure [10].

It would be prudent to watch your carbohydrate intake and regularly check blood sugar and insulin levels while taking ibutamoren.

As an anabolic, ibutamoren should be avoided if you have cancer. Both growth hormone and IGF-1 may promote cancer growth [27].

We would not recommend taking ibutamoren if you are Th1 dominant since growth hormone has immune-stimulatory properties.

Ibutamoren may cause muscle pain and heart failure. It can raise blood glucose, appetite, insulin resistance, blood pressure, and cancer growth.

Buy Ibutamoren

There are some vendors who sell Ibutamoren in the United States. You can get 10% off by using the code “selfhacked”.

Want Better Results from Your Training?

If you’re interested in natural and targeted ways of lowering your inflammation, we recommend checking out SelfDecode’s Fitness DNA Wellness Report. It gives genetic-based diet, lifestyle and supplement tips that can help improve your health and fitness. The recommendations are personalized based on your genes.

SelfDecode is a sister company of SelfHacked. This section contains sponsored links, which means that we may receive a small percentage of profit from your purchase, while the price remains the same to you. The proceeds from your purchase are reinvested into our research and development, in order to serve you better. Thanks for your support!

We at SelfHacked advise speaking to a doctor before taking any drug, especially an unscheduled drug with limited long-term safety data in humans.


Ibutamoren is an OTC drug that boosts growth hormone (GH) and IGF-1 while having no impact on cortisol and other hormones. Unlike other GH stimulators, it can be taken orally, once daily.

Bodybuilders use ibutamoren to build muscle and lose fat. Ibutamoren can also improve bone density and sleep. Users claim it has nootropic and wound-healing effects, but there are no studies to back this up.

On the downside, ibutamoren may cause leg swelling, muscle pain, and insulin resistance. In rare cases, it may increase blood pressure and cause heart failure. Cancer patients should avoid ibutamoren, since it may feed the growth of tumors.

About the Author

Biljana Novkovic - PHD (ECOLOGICAL GENETICS) - Writer at Selfhacked

Dr. Biljana Novkovic, PhD

PhD (Ecological Genetics)

Biljana received her PhD from Hokkaido University.

Before joining SelfHacked, she was a research scientist with extensive field and laboratory experience. She spent 4 years reviewing the scientific literature on supplements, lab tests and other areas of health sciences. She is passionate about releasing the most accurate science & health information available on topics, and she's meticulous when writing and reviewing articles to make sure the science is sound. She believes that SelfHacked has the best science that is also layperson-friendly on the web.

Click here to subscribe


1 Star2 Stars3 Stars4 Stars5 Stars
(45 votes, average: 3.91 out of 5)

FDA Compliance

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.