Ipamorelin common uses, half-life, side effects and more

Ipamorelin is a short synthetic peptide that makes the pituitary release its own growth hormone. It was built from the growth hormone releasing peptide series by cutting the molecule down. People choose it over its relatives because it is believed not to raise cortisol. That belief rests on a single study in pigs and has never been checked in a person. It has never been approved anywhere. Its only published trial in patients failed. The largest trial ever run on it finished in 2014 and was never published.

• Raising growth hormone without injecting growth hormone itself
• Recovery, sleep, and body composition (community use)
• Stacking with a growth hormone releasing hormone analog
• A gentler alternative to the older releasing peptides
• Historically tested for slow gut recovery after bowel surgery

Two or three times daily in community practice

Community practice is 200 to 300 mcg under the skin two or three times a day. That figure comes from bodybuilding forums catalogued in a review rather than from any trial. No human study has ever given ipamorelin under the skin. Every human dose on record went into a vein at 0.03 to 0.06 mg per kg. That works out near 2 to 5 mg for an adult and is far above the community amount. Compounding pharmacies dispense 3 to 15 mg vials but no source states the per-dose amount they intend. The commonly quoted cycle of 8 to 12 weeks on and 4 to 6 weeks off also comes from forums.

The measured half-life is about two hours. That figure comes from a 15 minute drip into a vein given to about 30 healthy men in 1999. No study has ever measured this peptide after an injection under the skin, in people or in any animal. The claim that 80 to 95 percent of a skin injection reaches the blood traces to a seller's page that also states 3 to 8 percent. The only bioavailability ever published for ipamorelin is about 20 percent by nose in rats. Growth hormone peaks around 40 minutes and is gone by six hours.

• Low potassium and raised blood sugar were more common than on placebo
• Trouble sleeping was also more common than on placebo
• Nausea, vomiting, and indigestion in the surgical trials
• Increased appetite and body fat in mice
• A blunted growth hormone response after two weeks of daily dosing in rats

Ipamorelin activates the ghrelin receptor on the pituitary and releases the body's own growth hormone. That raises IGF-1 from the liver. It acts directly on the pituitary and works on isolated pituitary cells with no brain attached. It is often said to work by lifting the brain's brake on growth hormone. No study has tested that for ipamorelin. Where it was tested for two relatives the release did not depend on lifting that brake. Its receptor affinity has never been published. The numbers in circulation measure effect rather than binding.

Three trials have given ipamorelin to people and all of them dosed into a vein. The first was a single-dose study in about 30 healthy men that measured only growth hormone. The second gave it to 114 patients after bowel surgery and missed its goal. No secondary measure differed either. The third enrolled 320 patients, finished in 2014, and was never published. That unpublished trial is the largest study of this compound ever run. The selectivity that makes people choose it was shown in conscious pigs by the company that made it. It has never been replicated or tested in a person. No controlled study has run longer than seven days.

• The FDA found serious adverse events including death when it was given into a vein for gut recovery and the published summary does not mention them
• The selectivity it is chosen for was shown only in pigs and no human study has ever measured cortisol after a dose
• The route people actually use has never been studied in a person or in any animal
• It sits on the FDA's list of bulk substances that raise significant safety risks
• Seized products have contained a modified version built to evade drug testing and imported material has been found hidden in shipments declared as something else
• Avoid it in pregnancy and breastfeeding since no data exist in any species