Hexarelin Calculator

What Is Hexarelin?

Hexarelin (also known as examorelin) is a synthetic hexapeptide belonging to the class of growth hormone releasing peptides (GHRPs). It is composed of six amino acids and is structurally derived from GHRP-6, but with a targeted modification of one tryptophan residue to D-2-methyl-tryptophan. This change gives Hexarelin greater metabolic stability and makes it one of the most potent members of the first generation of GHRPs. Hexarelin is supplied as a lyophilized powder and, for research purposes, is reconstituted with bacteriostatic water and administered subcutaneously or intramuscularly.

Hexarelin was studied intensively during the late 1980s and 1990s, originally as a candidate for the treatment of growth hormone deficiency. That period generated an unusually broad body of preclinical and early clinical evidence, which sets Hexarelin apart from many other research peptides. Alongside its strong release of growth hormone (GH), one striking finding was a distinct, GH-independent effect on the cardiovascular system that remains an active area of research today. This cardiac component clearly differentiates Hexarelin from more selective GHRPs such as ipamorelin.

Compared with other secretagogues, Hexarelin is considered exceptionally potent: each administration triggers a strong GH pulse. That strength has a trade-off, however, because research shows that Hexarelin is prone to pronounced desensitization of the pituitary system with continuous use. For this reason, research protocols typically use Hexarelin only in short, time-limited phases rather than treating it as a continuous-use peptide. Hexarelin is neither an approved drug nor an anabolic steroid; it works indirectly through the body's own GH axis.

Mechanisms of Action

Hexarelin exerts its effects primarily by activating the ghrelin receptor, which triggers a cascade of hormonal and tissue-specific responses:

• Ghrelin / GHS receptor agonism: Hexarelin binds to the growth hormone secretagogue receptor (GHS-R1a), the same receptor that the body's own hormone ghrelin acts on. Through this receptor, Hexarelin stimulates both the pituitary gland and the hypothalamus, mimicking a natural hormonal signal.
• Strong GH pulse: Receptor activation produces a strong, pulsatile release of growth hormone from the pituitary. Hexarelin is regarded as one of the most potent GHRPs in terms of the amplitude of this pulse. The GH rise is dose-dependent and can, downstream, stimulate the production of IGF-1 in the liver.
• Suppression of somatostatin: Through its hypothalamic action, Hexarelin dampens the inhibitory influence of somatostatin on GH release. As a result, the GH pulse is larger and longer than stimulation of the pituitary alone would allow.
• Cardiac research via the CD36 receptor: A distinctive feature of Hexarelin is its GH-independent binding to the cardiac CD36 receptor. In preclinical models, this pathway has been associated with effects on heart muscle tissue and cardiac function, for example after ischemic stress. This mechanism is independent and is observed even in subjects or animal models without an intact GH axis.
• Effect on cortisol and prolactin: Unlike highly selective GHRPs, Hexarelin can, at higher doses, produce a mild rise in cortisol and prolactin. This effect is weaker than with GHRP-2 but stronger than with ipamorelin, and it should be taken into account when planning doses.
• Receptor desensitization: With prolonged, uninterrupted use, the pituitary responds progressively more weakly to Hexarelin. This tachyphylaxis is well documented and is the main reason research protocols structure Hexarelin into short cycles with clear breaks.

Dosage Calculation

In research, Hexarelin is used in comparatively small amounts per administration and is typically dosed several times per day to mimic the body's natural pulsatile GH release. Because of its marked tendency toward desensitization, higher doses are not automatically better, and a conservative approach is sensible.

Standard Dosing Parameters

• Conservative dose: 50 mcg (0.05 mg) per administration
• Standard dose: 100 mcg (0.10 mg) per administration
• Higher range: 150–200 mcg (0.15–0.20 mg) per administration
• Frequency: 2–3 times daily, with at least 3–4 hours between administrations
• Timing: On an empty stomach, since dietary fats and carbohydrates can blunt the GH pulse; common practice is one dose after waking, one before bed, and optionally one after training
• Typical syringe: 0.3 mL insulin syringe (29–31 gauge, 6–8 mm needle)

Example Calculation: 5 mg Vial with 2 mL BAC Water

Hexarelin is commonly available in 2 mg and 5 mg vials. Reconstituting a 5 mg vial with 2 mL of bacteriostatic water produces a concentration of 2.5 mg/mL (2,500 mcg/mL).

• 50 mcg dose: 50 ÷ 2500 = 0.02 mL (2 units on a U100 syringe)
• 100 mcg dose: 100 ÷ 2500 = 0.04 mL (4 units)
• 150 mcg dose: 150 ÷ 2500 = 0.06 mL (6 units)
• 200 mcg dose: 200 ÷ 2500 = 0.08 mL (8 units)

At a standard dose of 100 mcg administered three times daily, 300 mcg is used per day. A 5 mg vial therefore lasts roughly 16–17 days. Because Hexarelin is dosed in small volumes, a precise syringe with fine graduations is important. Use the Hexarelin calculator above to determine exact volumes for any vial size, reconstitution volume, and target dose.

Reconstitution

Hexarelin is supplied as a lyophilized (freeze-dried) powder in sealed vials and must be reconstituted with bacteriostatic water (BAC water) before use in research settings. BAC water contains 0.9% benzyl alcohol, which inhibits microbial growth and extends the usable window of the reconstituted solution. Sterile water for injection is not suitable for multi-dose vials.

Step-by-Step Reconstitution Protocol

1. Gather supplies: Hexarelin vial, bacteriostatic water vial, alcohol swabs, a sterile draw needle (18–21 gauge), and your insulin syringe for administration.
2. Wipe the rubber septa of both vials with fresh alcohol swabs and let them air-dry for about 30 seconds. Do not touch or blow on the septa afterward.
3. Draw the desired volume of BAC water (2 mL is common for a 5 mg vial) into the draw syringe.
4. Insert the needle into the Hexarelin vial at an angle, directing the tip toward the inner glass wall rather than the powder cake. Spraying BAC water directly onto the powder can shear peptide bonds and damage the molecule.
5. Slowly push the plunger so that the BAC water runs down the inside wall of the vial and gently wets the powder from below.
6. Carefully roll or gently swirl the vial between your palms until the powder has fully dissolved. The solution should appear clear and colorless. Do not shake or vortex.
7. Label the vial with the reconstitution date and concentration (e.g., "Hexarelin 2.5 mg/mL — reconstituted [date]").

If the solution appears cloudy, discolored, or contains visible particulate matter, discard the vial and do not use it.

Storage and Shelf Life

• Lyophilized powder (unreconstituted): Store at −20°C for long-term storage, where the powder remains stable for many months. Short-term storage at 2–8°C in a refrigerator is acceptable. Keep away from light and moisture, and do not leave at room temperature for extended periods.
• Reconstituted solution: Store in the refrigerator at 2–8°C. The solution is typically stable for around 2–3 weeks. Keep the vial upright and away from light, and write the reconstitution date prominently on the label.
• Do not freeze reconstituted peptide. Freeze-thaw cycles cause protein aggregation and loss of biological activity. Once reconstituted, the vial must remain refrigerated throughout its use window.
• Transport: Use an insulated cooler with an ice pack for any travel lasting more than 1–2 hours. Commercial insulated medication pouches maintain 2–8°C for 24–48 hours. Avoid exposure to temperatures above 25°C during transport.

Side Effects and Safety Profile

Hexarelin was studied in several early clinical trials during the 1990s and was generally well tolerated in those short-term settings. Nonetheless, large-scale long-term human data is lacking, so all use remains in the research domain. The side effects arise mainly from its mechanism as a ghrelin receptor agonist.

Commonly Reported Observations

• Pronounced hunger, since activation of the ghrelin receptor stimulates appetite. This effect is moderate with Hexarelin, sitting between the strong hunger seen with GHRP-6 and the minimal appetite effect of ipamorelin.
• Water retention, transient tightness in the hands, or mild joint stiffness, which are associated with GH release and are dose-dependent.
• Mild redness, brief discomfort, or a sensation of warmth at the injection site, which usually resolves within a few hours. Rotating injection sites reduces localized irritation.
• Tiredness or drowsiness after administration, especially with the evening dose, which some users find pleasant for sleep.

Less Common or Theoretical Concerns

• Rise in cortisol and prolactin: At higher doses, Hexarelin can slightly elevate cortisol and prolactin. Sustained elevated prolactin could theoretically contribute to hormonal side effects, so higher doses should be chosen with care.
• Receptor desensitization: The most distinctive characteristic of Hexarelin is its rapid tachyphylaxis. With continuous use over several weeks, the GH response noticeably declines. This is not an acute safety risk but reduces effectiveness and necessitates cyclical use.
• Effect on insulin sensitivity: Sustained elevated GH activity can theoretically alter insulin sensitivity. Research models that track glucose parameters should take this aspect into account.
• Cardiac CD36 activity: The GH-independent effect of Hexarelin on heart tissue is the subject of ongoing research. Its long-term consequences are not fully characterized, so particular caution is appropriate where pre-existing cardiovascular factors are present.

Contraindications

• Active cancer or history of malignancy (without medical supervision)
• Pregnancy and breastfeeding (insufficient safety data)
• Known hypersensitivity to any component of the preparation
• Existing pituitary disorders or untreated endocrine conditions

No serious adverse events have been reported in the short term at the research doses described in the literature. Given the absence of long-term human data, caution is warranted, and consultation with a qualified healthcare professional is strongly recommended.

Combinations and Stacks

Hexarelin with a GHRH Analog

The most common research approach combines a GHRP such as Hexarelin with a GHRH analog, for example CJC-1295 without DAC. The two compound classes act through different receptors and complement each other: the GHRP increases the amplitude of the GH pulse, while the GHRH analog primes the pituitary for release. In preclinical studies, this combination produces a stronger GH pulse than either compound alone. Both peptides are reconstituted separately and dosed immediately before administration.

Hexarelin Compared with More Selective GHRPs

Within the GHRP class, Hexarelin is positioned as the most potent but least selective peptide. Ipamorelin is regarded as the most selective GHRP, with minimal influence on cortisol, prolactin, and appetite, and is therefore often preferred for longer research phases. GHRP-2 and GHRP-6 sit in between, with GHRP-6 showing the strongest appetite effect. In research, Hexarelin is typically used when a particularly strong GH pulse is the focus and the protocol is planned to be time-limited anyway.

Cycle Design Rather Than Continuous Use

Because of its pronounced desensitization, Hexarelin is rarely run as a continuous-use peptide in research protocols. Short cycles of a few weeks, followed by a break or a switch to a more selective GHRP such as ipamorelin, are common. This rotation is intended to preserve pituitary sensitivity. Related secretagogues such as Sermorelin are also used in research within rotation and comparison protocols.

Frequently Asked Questions

How does Hexarelin differ from ipamorelin?

Both are GHRPs and activate the same ghrelin receptor, but they differ in potency and selectivity. Hexarelin produces a stronger GH pulse but can, at higher doses, slightly raise cortisol and prolactin and tends to desensitize quickly. Ipamorelin is weaker but highly selective and better suited to longer research phases. The choice depends on whether a short, strong pulse or a more stable, sustained application is the priority.

Why is Hexarelin only used in cycles?

Hexarelin shows pronounced tachyphylaxis: with continuous use, the pituitary responds progressively more weakly to the peptide, and the GH pulse becomes smaller over time. Short cycles with clear breaks, or a switch to a more selective GHRP, are intended to preserve receptor sensitivity and counteract this fading response.

Should Hexarelin be administered on an empty stomach?

In research, Hexarelin is usually dosed with some separation from meals, since dietary fats and larger amounts of carbohydrates can blunt the GH pulse. A gap of roughly one hour before or after eating is common practice. A dose before bed is frequently scheduled on an empty stomach.

What is the cardiac CD36 effect of Hexarelin?

In addition to the ghrelin receptor, Hexarelin binds to the CD36 receptor in heart tissue. This pathway is independent of GH release and has been studied in preclinical models in relation to cardiac function. It is an active research field whose long-term significance is not yet fully established.

Does Hexarelin increase appetite?

Yes, to a moderate degree. Because Hexarelin acts on the ghrelin receptor, it can increase hunger. The effect is clearly weaker than with GHRP-6 but stronger than with ipamorelin, which shows almost no appetite effect.

How long does a typical Hexarelin research cycle last?

Because of its rapid desensitization, research protocols generally use short cycles of a few weeks, followed by a break. Longer uninterrupted phases are atypical, because the GH response then noticeably declines. The exact duration depends on the study design.

Can Hexarelin be combined with a GHRH analog?

Yes. Combining a GHRP with a GHRH analog is the most common research approach, since the two act through different receptors and complement each other. The two peptides are reconstituted separately and dosed immediately before administration to avoid stability concerns.

Is Hexarelin prohibited in sport?

Yes. Growth hormone secretagogues and GHRPs are listed on the WADA prohibited list as banned substances and are prohibited at all times. Athletes subject to anti-doping testing should treat Hexarelin as a prohibited substance and verify the rules applicable to their sport before any use.

Medical Disclaimer: The information on this page is provided for educational and research purposes only. Hexarelin is not an approved drug or medical treatment and is supplied strictly for research use. Nothing on this page constitutes medical advice, diagnosis, or a recommendation to use any specific compound. Always consult a qualified healthcare professional before beginning any peptide protocol. BergdorfBio assumes no liability for the use or misuse of the information presented here.