MK-677 vs CJC-1295: what to choose and for whom

In the question “MK-677 or CJC-1295” people usually weigh convenience: a pill versus an injection, appetite versus its absence. The editorial team offers a different angle — in terms of health, medical indications and real alternatives. Spoiler: for most people the right answer is not in this pair.

What people expect and what they get

A lot is expected of growth-hormone stimulators: better sleep, faster recovery, fat burning, muscle growth, “rejuvenation” of the skin and joints. Yet the clinical data are far more modest. In a year-long study of MK-677 in elderly people (Nass et al., 2008) lean mass increased, but strength and functional indicators did not change substantially.

For CJC-1295, mainly data are available on how much and for how long GH and IGF-1 rise after administration. There are no studies that would show a benefit for body composition or athletic performance in healthy people.

This is an important point: a rise in a hormone level on a test does not yet mean clinical benefit. Even for recombinant growth hormone, a systematic review of studies in healthy young people (Liu et al., 2008) showed an increase in lean mass without a clear improvement in strength or endurance, and part of the gain may have been related to fluid retention.

So before choosing an “instrument”, it is worth honestly determining what problem it is meant to solve — and whether there is not a simpler, safer solution for it.

Practical differences that affect risk

MK-677 is taken by mouth and acts for a long time. Its characteristic effect is a strong increase in appetite, since it mimics ghrelin. For a person trying to lose weight, this directly works against the goal. In addition, in studies ibutamoren raised fasting glucose and reduced insulin sensitivity.

CJC-1295 is an injectable peptide. This adds risks related to the injection itself: infections, injection-site reactions, contamination of the solution. On the illegal market these risks are amplified by the absence of guarantees of sterility and of the true contents of the vial.

In addition, under the name “CJC-1295” at least two different compounds are sold — with DAC and without it — with radically different durations of action. The buyer often does not know exactly what they are getting.

Common to both: they have no registered medical indications, and therefore no approved instructions, contraindications or pharmacovigilance system.

For whom these substances are contraindicated first of all

Stimulation of the GH/IGF-1 axis has classic contraindications that also apply to registered drugs of this group. For unregistered substances they are all the more relevant.

• Active cancers or a history of cancer— IGF-1 is a cell growth factor.
• Diabetes mellitus, prediabetes, insulin resistance— especially for MK-677.
• Heart failure, a tendency to edema— fluid retention; in a study of MK-677 after hip fracture a signal for heart failure was observed.
• Children and adolescents— interference with growth processes.
• Pregnancy and breastfeeding.
• Athletes under doping control— both substances are banned by WADA (class S2).

It is also worth being careful for people with carpal tunnel syndrome, joint pain or sleep apnea: a rise in GH/IGF-1 can worsen these conditions.

Older people interested in these substances as “anti-aging” agents should know that it is precisely in the elderly that the most notable metabolic side effects have been found, while a benefit for function has not been proven.

For the remaining adults the argument is the same as for other unregistered hormonal substances: unknown long-term safety plus unknown product quality.

What to find out with a doctor and in lab tests

If a person suspects they have a growth-hormone deficiency — for example, after a head injury, pituitary surgery or in the presence of characteristic symptoms — the diagnosis is made by an endocrinologist. A single GH test is not very informative because of the pulsatile secretion; IGF-1 is assessed and, if necessary, stimulation tests are performed.

Confirmed GH deficiency in adults is treated with recombinant growth hormone according to the Endocrine Society clinical guidelines (Molitch et al., 2011) with regular monitoring of IGF-1, glucose and other indicators.

For those who have already used MK-677 or CJC-1295, it is reasonable to check fasting glucose, glycated hemoglobin and IGF-1 and to discuss the results with a doctor. It is important to report the fact of use openly — this helps to interpret the tests correctly.

The appearance of edema, numbness of the fingers, joint pain or thirst with frequent urination is a reason to see a doctor without delay.

How to support natural GH secretion

The most powerful natural stimulator of growth-hormone secretion is deep sleep: a significant part of the daily secretion falls in the first hours of night sleep. A regular schedule, sufficient sleep duration and treatment of apnea give a physiological effect without risks.

Intense physical loads, in particular strength and interval training, acutely increase GH secretion. Reducing excess fat mass also helps normalize secretion, since in obesity it is suppressed.

For recovery and building muscle mass, sufficient protein, creatine monohydrate and a properly planned training process work in an evidence-based way. These tools require no intervention in the hormonal system.

Finally, one should be skeptical of supplements that promise to “naturally raise growth hormone” through amino acids: acute fluctuations in GH after such supplements do not necessarily mean a benefit for body composition.

Editorial conclusions

MK-677 and CJC-1295 differ in form, mechanism and structure of risks, but both substances are unregistered, banned in sport and have no proven benefit for healthy people. MK-677 is especially problematic for people with glucose-metabolism disorders and a tendency to edema; CJC-1295 adds the risks of injection and of confusion between product versions.

If there is a suspicion of growth-hormone deficiency, there is one path — an endocrinologist and diagnostics. If the goal is shape and recovery, the basic tools work better than they seem.

We also recommend reading “MK-677 or CJC-1295: what is the difference”, our material on IGF-1 as a laboratory indicator and an article on sleep and recovery.

References

1. Nass R, Pezzoli SS, Oliveri MC, et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008;149(9):601–611.
2. Teichman SL, Neale A, Lawrence B, et al. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. J Clin Endocrinol Metab. 2006;91(3):799–805.
3. Adunsky A, Chandler J, Heyden N, et al. MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study. Arch Gerontol Geriatr. 2011.
4. Molitch ME, Clemmons DR, Malozowski S, et al. Evaluation and treatment of adult growth hormone deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(6):1587–1609.
5. Liu H, Bravata DM, Olkin I, et al. Systematic review: the effects of growth hormone on athletic performance. Ann Intern Med. 2008;148(10):747–758.
6. World Anti-Doping Agency. The World Anti-Doping Code International Standard: Prohibited List. Montreal: WADA; чинна редакція.