GHRP-6 is a growth hormone secretagogue. It is a first generation Growth Hormone Releasing Peptide (GHRP) to be more specific, one of the earliest drugs of this class to effectively raise serum GH. This agent is an agonist of the growth hormone secretagogue receptor la (GHSRIa). It acts on these receptors in the hypothalamus and pituitary, which stimulates the release of growth hormone. Liver IGF-1 (Insulin-like Growth Factor 1) may also be increased as a result. Provided an ample dose is given, the resulting GH spike from GHRP-6 can reach supraphysiological (higher than normal) levels, although there have been more potent drugs of this class to come after it. This agent is still widely used in the sports community though, most commonly as an appetite stimulant, and to support muscle growth and fat loss alongside other drugs. GHRP's are all based on Ghrelin, a gastric peptide hormone. Ghrelin is secreted by the stomach during times of fasting (between meals). It has activity in a wide range of body tissues including the brain and the sympathetic nervous system, the stomach, heart, pancreas, liver, and intestines, and even adipose tissue. Though its physiological effects are also diverse, this hormone is largely identified as helping to regulate food intake, body composition, and glucose metabolism. While all GHRPs are modeled after ghrelin, each has its own activity profile. Many are more selective toward GH elevations than the category's natural parent hormone. GHRP-6 is an early GHRP, and not regarded as highly selective. Though it does trigger substantial increases in serum growth hormone, there is also spillover in other areas. For one, GHRP-6 has a tendency to mildly increase ACTH (adrenocorticotropic hormone), cortisol, and prolactin levels. This may result in some unwanted side effects, especially if these hormones go beyond normal values (see Side Effects). Note, these levels seem to rise less noticeably than with GHRP-2. Like ghrelin and many drugs of the GHRP class, GHRP-6 is also noted for stimulating appetite and gastric motility. The orexigenic (appetite stimulating) effects are among the most notable features of this drug, in fact, and generally more intense than GHRP-2 and other GHRPs. Unless diet is controlled, use of this drug usually coincides with a notable increase in caloric intake.
GHRP-6 Key Points
- Strong Increase in Appetite
- Moderate Effect on GH
- Mild Elevations in Cortisol
- Mild Elevations in Prolactin
GHRP-6 was first described in 1984 by Bowers et al. It is among the earliest and most visible representatives of the growth hormone releasing peptides class of drugs. It has also been subject to the most study, including a great deal of investigation in human subjects. As research on GHRPs progressed throughout the 1990s, many new compounds began to take stage. Though the safety on GHRP-6 appeared to be very high, and its efficacy at increasing serum growth hormone more than acceptable, it slowly began losing favor to other more potent or selective GHRPs such as GHRP-2, hexarelin, and ipamorelin. Still, this drug became popular with compounding pharmacies in the United States during the mid 2000s, and remains so to this day.
GHRP-6 is on the World Anti-Doping Agency's (WADA) list of prohibited substances. Screening for this drug began on a large scale during the 2014 Winter Olympics in Sochi. This drug is now specifically detectable, at least for a short window after use, during routine urine analysis. A blood sample is not required.
How is GHRP-6 Supplied
GHRP-6 is not available as a pharmaceutical product. Compounded and gray market versions typically contain 5 mg or 10 mg of dry lyophilized powder in a multi-dose vial. This is reconstituted with a diluent (sterile water or bacteriostatic water) before use.
Structural Characteristics of GHRP-6
GHRP-6 is a synthetic hexapeptide with the chemical name His-D-Trp-Ala-Trp-D-Phe-Lys-NH2. This is a short peptide chain, which is relatively stable. GHRP-6 has a half-life in serum of approximately 20 minutes. It displays a low level of bioavailability via oral administration (.3%), and an acceptable level of bioavailability via intranasal administration (~ 30%). IM or SC routes are preferred with this compound.
GHRP-6 should be used with care in epileptic patients. Obesity, uncontrolled hypothyroidism, hyperglycemia, or elevated plasma fatty acids may impair the effectiveness of GHRP-6. This drug should never be used during pregnancy, with cancer, a history of cancer, diabetic retinopathy, sclerosing diseases of the liver or lungs, intracranial hypertension, or uncontrolled diabetes.
GHRP-6 Side Effects (General)
Common side effects to GHRP-6 therapy include flushing, sweating, sleepiness, increased Gi motility, and increased appetite. Elevations in prolactin may also be a concern for individual with preexisting gynecomastia. Also frequently reported with GHRP-6 are adverse effects typically associated with other types of growth hormone therapy, such as water retention (edema), joint pain (arthralgias), carpal tunnel syndrome, and numbness or tingling in the extremities. Note that the incidence of side effects tends to be lower with GHRP therapy as compared to traditional hGH. This is because GH/IGF-1 release is subject to endogenous synthesis, and as such the drug is less amenable to overdosing.
GHRP-6 Side Effects (Injection site)
The subcutaneous administration of this drug may cause redness, itching, pain, or lumps at the site of injection. Injection site redness and discomfort is sometimes reported with intramuscular injection as well.
GHRP-6 Side Effects (Impaired glucose tolerance)
GHRP-6 may reduce insulin sensitivity and raise blood sugar levels. This may occur in individuals without preexisting diabetes or impaired glucose tolerance.
GHRP-6 is given by subcutaneous (SC) or intramuscular (IM) injection.
When used for physique- or performance-enhancing purposes, GHRP-6 is usually administered at a dosage of 0.1 to 0.3 mg (100-300 meg) per injection. This may be given 1 -3 times daily. If single episode dosing is preferred, this may be taken before sleep. Day dose(s) are taken on an empty stomach, 30-60 minutes before feeding. This is to preserve optimal GH release, as elevated plasma fatty acids and/or glucose may blunt the GH elevating effects of GHRP-6. Total daily dosage of GHRP-6 generally does not exceed 900 meg.
It is common to taper up the dosage, beginning with 100 meg per injection. The dosage may then be increased in increments of 50 meg every 3-7 days, until a stable dosage is reached.
Cycles of GHRP-6 usually last 3-4 months in length, though programs of 6 months or longer are not uncommon. Although desensitization to GHRPs may occur over time, this drug appears to maintain an acceptable level of effectiveness during longer cycles.
GHRP-6 Combination Therapy
Drugs of the GHRP class are often combined with those of the GHRH (Growth Hormone Releasing Hormone) category, such as sermorelin or CJC-1295. These two drug types alter GH release through two distinct and complimentary mechanisms. Such combination therapy produces substantial synergy with regard to GH release, producing maximum GH elevations that are much higher than noted with either drug alone. Note that injections of GHRP-6 are typically reduced to no more than 200 meg each during combination therapy, and 600 meg total per day.
Below is an example of combination therapy with GHRP-6.
GHRP-2: 100-200mcg 1-3x daily
GHRP-6: 100-200mcg 1-3x daily
Sermorelin: 100-200mcg 1-3x daily
GHRP-6 is available in the United States as a compounded medicine, and is often offered at anti-aging and hormone replacement clinics. It is also sold as a gray market "research compound" though the quality of gray market GHRP-6 products can be difficult to assure.
Wlliam Llewellyn (2017) - Anabolics