Ibutamoren (MK-677) Review

What is MK-677? What effects can you expect from using it? Does it have any side effects? What should you be aware of before buying? I will answer these and other questions in the following article. 

What is MK-677?

Ibutamoren, also known as MK-677 and Nutrobal, is a substance created at the beginning of the 21st century by Merck & Co. 

Often mistakenly categorized as SARM (Selective Modulators of Androgen Receptors) or called growth hormone in tablets. 

sarm mk677 capsulesIt is a substance that stimulates the secretion of growth hormone and insulin-like growth factor IGF-1. This means that Nutrobal does not directly affect the level of these hormones, but only indirectly signals to the body to produce more of them. 

It binds to the GHSR receptors, thus it also affects all the functions associated with them – appetite, mood, memory, biological rhythm and cognitive skills.

Ibutamoren is currently being studied for its ability to prevent muscle wasting and obesity diseases, increasing bone density and as a cure for hormone deficiency. Recent results of clinical trials confirm reviews of people using MK-677 so far, proving that high hopes placed in this substance were not unfounded. 

Ibutamoren MK77 Result Before and after

Serum insulin-like growth factor I (IGF-I) increased approximately 40% with MK-677 treatment (P < 0.001 vs. placebo). Serum IGF-binding protein-3 was also significantly increased (P < or = 0.001 vs. placebo). –  Two-Month Treatment of Obese Subjects with the Oral Growth Hormone (GH) Secretagogue MK-677 Increases GH Secretion, Fat-Free Mass, and Energy Expenditure [ResearchGate]

MK-677 Benefits

  • Accelerates muscle growth
    One of the advantages which makes Ibutamoren so popular is its anabolic effects. It increases the secretion of growth hormone, which accelerates regeneration and allows longer and more frequent trainings, and IGF-1 (insulin-like growth factor) which is one of the most anabolic hormones naturally occurring in the human body.
    Due to its anabolic activity, MK-677 helps not only to build muscles but also to shed fat. However, it is relatively rarely used for this purpose due to water retention.
    As part of a double-blind, random and controlled trial, 24 obese men were given MK-677 for a period of 2 months. During this period, all patients had increased basal metabolism (BMR) and increased lean body mass. 
  • Reverses the effects of muscle wasting diseases.
    In another double-blind, random and controlled study, eight volunteers were subjected to prolonged starvation. In three of them, MK-677 was able to reverse the effects of chronic protein deficiency and muscle wasting due to inadequate diet. 
  • Increases bone density
    No one should be surprised that Ibutamoren can increase bone density as it is the growth hormone that is responsible for this process.
    Research confirms this theory. In three double-blind, random and controlled tests, MK-677 significantly increased bone density in people over the age of 65. Similar results were obtained in the study on 292 women who had undergone menopause – all of them improved bone strength as a result of increased mineralization.
    An interesting fact was also observed in the study; that is, as it turns out, Ibutamoren influences the bone turnover. In the initial stage it inhibits it, and in the later stage it accelerates. This means that in some cases, it may take up to 12 months for effect to occur. 
  • Regenerates joints
    One of the most popular applications of Ibutamoren among gym users. Due to the secretion of growth hormone, it significantly accelerates the regeneration of all body tissues, including joints. Steroid users very often use it between cycles not only to regenerate joints that are often overloaded with anabolic steroids, but also to maintain most of the muscle gain. 
  • Improves sleep quality
    In clinical trials, Ibutamoren improved sleep quality in all subjects, extending the REM phase. In addition to the research, there are also hundreds of user testimonials confirming this effect. Unfortunately, it is sometimes too apparent – many people who use this product have complained about lethargy during the day. 
  • Skin, hair and nails
    Both while using Ibutamoren as well as growth hormone, our skin, hair and nails improve their appearance. It is worth pointing out that this substance significantly accelerates the growth of hair and nails. Many users claim that during the cycle their skin acquires a characteristic “glow” for which they often receive compliments. Unfortunately, this effect disappears within about a month after the discontinuation of use.
  • Longevity
    The amount of secreted growth hormone significantly decreases when the puberty ends. It is one of the hormones responsible for keeping our cells in good shape. Therefore, many people argue that taking growth hormone or substances that increase its secretion can prolong life.
    Interesting fact: Peter Thiel (founder of Paypal) admits to taking growth hormone in order to live to 120 years. 
  • Procognitive effects
    Nootropic effects of this substance are related to

    1. Increased secretion of IGF-1 which improves memory and cognitive abilities
    2. Improved quality of sleep, thanks to which we are more relaxed and more easily assimilate new knowledge
    3. Increase in the amount of secreted growth hormone that affects the speed of building new neurons
  • Prevents deficiency of growth hormone
    As we have already mentioned many times in this article, Ibutamoren increases the secretion of growth hormone, IGF-1 and IGFBP-3. This is particularly important in the case of children and adolescents suffering from a deficiency of these hormones. Research shows that Ibutamoren can be a great alternative to conventional therapies because it does not interfere with the production of other hormones. 
  • Accelerates wound healing
    Although no studies are confirming this effect when it comes to Ibutamoren, common sense suggests that this should be so. 

Side Effects

Unfortunately, despite a large list of advantages, Ibutamoren also has side effects. 

The first one is the increased sluggishness during the day. Fortunately, most people manage to avoid it by taking the substance before bed. (In a few people, morning administration does not cause sluggishness, while evening administration does. If you notice this problem yourself, try taking it at a different time) 

The next one is an increased appetite. Ibutamoren increases the secretion of ghrelin, commonly known as the hormone of hunger. Unfortunately, this side effect cannot be avoided in any way. While this is not a problem, when bulking or during Post Cycle Therapy, it is a serious problem during cutting. That is why not many people use this substance for this purpose, even though it increases the basic calorie requirement of the body, so in theory, it facilitates reduction. 

When using MK-677, it is also common for increased water retention to occur. While it does not mean that we will immediately look like a Michelin man, which is the case with some steroids, it is a certain disadvantage, especially for people with a low level of body fat.

MK-677 Results

Ibutamoren is an excellent substance for regeneration or as an addition to other SARMs/steroids. It speeds up building muscle mass but is not as strong as other SARMs. 

My personal experience

I started using MK-677 back in the days when I was using steroids. At that time, I used it mainly in the periods between cycles. It regenerates joints perfectly and allows you to maintain more gains. Due to its method of action, it does not interfere with sex hormones so it can be used even during PCT. It’s hard for me to say how much mass can be built on a solo cycle, but I wouldn’t expect spectacular effects. During ‘cycle’, you can certainly see the water retention – in my case, it is usually about 2kg, but I know people in whom this number can be even twice as big.

I also used Ibutamoren in combination with other SARMs and was very satisfied with the effects. Like Ostarin, MK-677 is also suitable as an addition to virtually every steroid/sarm cycle showing synergy effects. The only downside is the price, which is quite high in relation to the effects and required time of use. 

MK-677 before and after

MK-677 Dosage

Most people who use Ibutamoren choose to go with 20-30mg. For cutting I would suggest 20mg per day, and for regeneration or bulking 30mg. Some individuals decided to try much higher doses – 100mg but did not experience significantly better results. 

Ibutamoren can be used all year round without a break if our wallet allows us to do so.

Most people prefer to use MK-677 before bedtime to avoid problems with sluggishness during the day. 

Best place to buy MK-677

Unfortunately, the content of most products sold as SARMs has little to do with the label. Due to the high cost of SARMs in wholesale, most products have less substances than declared. An even more popular solution used by retailers is adding anabolic steroids or prohormones. For this reason, SARMs should only be purchased from reliable suppliers who have a certificate of analysis for each batch. 

Proven Peptides

proven peptides logo

The most popular shop in the world at the moment. They offer SARMs only in the form of a solution. Each product comes with a pipette and information on how many drops corresponds to one millilitre. On their website, there is a phone number so that any ambiguities can be resolved within a few minutes. They provide a certificate of analysis for each product, which can be obtained by sending them an e-mail. The company offers a loyalty program “Peptide points” in which we collect points that reduce the cost of future orders. Shipping from the USA.
Click here to check price


chemyo logo

The store has been present on the market for about two years. It quickly gained popularity on forums and Reddit thanks to good quality products at affordable prices. Like Proven Peptides, they only offer SARMs in the form of solutions. Unfortunately, the product does not come with a pipette. You need to buy a syringe (available on the website) or another liquid measuring device. Certificates of Analysis for each product can be found on the site. Shipping from the USA.
Click here to check price


swisschems logo

Relatively new store. It is not very popular at the moment, probably due to high prices.  Their products have a higher purity than most of the products on the market (about 0.5-1% higher). They sell not only SARMs but also Aromatase Inhibitors and PCTs. The products are in the form of tablets, which are considered by many to be a more convenient option. They have a certificate of analysis for each product. Shipping from the USA.
Click here to check price 


Although it has been our favourite shop for a long time, we are forced to change our recommendation. In recent months, contact with them has become difficult, parcels are delayed, and there is a lot of negative feedback on the effectiveness of their products. I apologize to all the people who bought their products in recent months based on my recommendation. 

Frequently Asked Questions

When to take mk677?

The time of administration does not affect the absorbability of the substance. However, most people choose to take it in the evening before bedtime to avoid problems with lethargy during the day. Yet, few people have better luck with morning dosage, so you should take the substance at different times during the first week to see what works better for you. 

Can females use MK-677?

Yes – Ibutamoren is completely safe. It only affects the level of growth hormone and IGF-1. It can be used by women, children, elderly, etc. 

Does MK-677 cause cancer?

There is no indication that Ibutamoren can cause cancer. Of course, it should not be given to people who already have cancer, because increasing the level of growth hormone and IGF-1 can accelerate its development. 

MK-677 half-life

The half-life in oral use in humans is approximately 24 hours.

MK677 cycle length

Ibutamoren can be used without breaks all year round. The only limitation is our wallet and our goals.

Is MK-677 legal?

At the time of writing this article, Ibutamoren is legal in USA and the majority of other countries.