Can a drug that was designed with the purpose to enhance the body’s natural rhythm actually cause the opposite effect? 

This is a question that has been posed by many when referring to growth hormone releasing peptides (GHRPs).

GHRPs have gained traction for their capabilities of enhancing the level of growth hormone (GH) in the body in cases of GH deficiency. 

Instead of replacing the hormone, GHRPs stimulate the body to produce GH on its own.

This has led researchers to ask whether enhancing GH release through GHRPs strengthens or potentially blunts the body’s own regulatory cycle over prolonged use.

What are Growth Hormone Releasing Peptides (GHRPs)? 

GHRPs are peptides that stimulate the pituitary gland to release natural GH. Their mechanism encourages the body to produce more of its own GH in a pulsatile manner (Sigalos et al.)

GHRP’s mechanism involves the activation of ghrelin receptors (GHS-R1a), key regulators of growth hormone release and metabolic balance

GHS-R1a’s natural ligand is the hormone ghrelin. 

Ghrelin is known as the “hunger hormone” and plays a role in appetite regulation, energy balance and GH release.

As GHRPs act on ghrelin receptors, GHRPs can mimic the effects of ghrelin. Therefore, they can influence metabolism, appetite and energy homeostasis.

The most common and well known GHRPs are:

• CJC-1295/Ipamorelin
• GHRP-2

Ipamorelin is a highly selective GHRP that has minimal side effects. It is commonly stacked with CJC-1295, working together to stimulate GH pulses. Ipamorelin is generally well tolerated and suitable for long-term use.

Hexarelin is the most potent GHRP in terms of GH release. Prolonged usage poses a greater risk of receptor desensitisation. Hexarelin is typically used in short-term protocols.

MK-677 (Ibutamoren) is a GHRP-mimetic as it is not a true peptide. It is an oral ghrelin receptor agonist and acts like a long-acting GHRP. MK-677 increases GH levels over time and has a long half-life. 

Synthetic GH vs GHRPs

Mechanism of Action:

Synthetic GH introduces recombinant human GH (rhGH) directly into the bloodstream.

Synthetic GH bypasses the natural hypothalamic-pituitary axis and suppresses endogenous GH release.

GHRPs work indirectly by stimulating the pituitary gland to release natural GH via the activation of GHS-R1a ghrelin receptors. GHRPs mimic the body’s natural GH pulsatile rhythm without overriding the body’s normal endocrine control.

Peptide Structure:

Synthetic GH is a 191-amino acid long polypeptide that is chemically identical to endogenous GH. It has a complex structure that requires precise handling and storage.

GHRPs are generally shorter synthetic peptides, ranging from around 5 – 8 amino acids in length. They are also more stable than synthetic GH and are easier to manufacture and store.

Spectrum of Use:

Synthetic GH has been FDA-approved for growth hormone deficiency, short stature due to Turner syndrome, and HIV-associated muscle wasting. 

It is also used for alternative indications like anti-aging and body recomposition purposes, though this is with more regulation.

GHRPs are very popular in fitness, injury recovery, anti-aging and sleep support. 

They are usually used in combinations with GHRHs (e.g. CJC-1295) to amplify GH output using two pathways. Stacking both types of peptides facilitates hormonal balance.

Safety and Tolerance:

• Usage of synthetic GH has higher risks of side effects when used long-term such as insulin resistance, organ enlargement and joint pain. It can also suppress natural GH production after long term usage.
• GHRPs are generally well tolerated, Ipamorelin in particular, as there is minimal impact on cortisol or prolactin levels. There is also a lower risk of suppression as they enhance the rhythm of natural GH secretion rather than replace it.

Potency and Predictability:

• Synthetic GH is very potent and has a direct, measurable impact on growth and body composition. Its effects are predictable but are less physiologic.
• GHRPs have a more gradual and natural type of result as their effects may take weeks to observe. Their potencies vary depending on the type of GHRP and dosing protocol.

Route of Administration and Dosage

Both synthetic GH and GHRPs are given by subcutaneous injection. 

Synthetic GH is typically taken once daily in the evening, with dosing based on weight, age, and GH deficiency. 

GHRPs are usually injected once or twice daily around sleep or fasting to mimic natural GH pulses, with lower doses often stacked with GHRHs.

Regulatory Status

Synthetic GH is a prescription-only medication. It is regulated by the FDA and EMA and is approved for treatment of GH deficiency, Turner syndrome and HIV-related muscle wasting. 

GHRPs are currently classified as research compounds only. They are not FDA approved for therapeutic purposes in humans but can be purchased here for research purposes.

Frequently Asked Questions (FAQs)

Do GHRPs suppress natural growth hormone production?

No. GHRPs stimulate the body’s natural release of GH and unlike synthetic GH they do not suppress natural GH production when used properly.

Are GHRPs safe for long-term use?

Many GHRPs, especially Ipamorelin, have shown good tolerance and safety profiles in long-term studies. However, more potent options like Hexarelin can lead to receptor desensitisation if overused. Supervision by a qualified clinician throughout long term usage is highly recommended.

Are there side effects to using GHRPs?
Most users tolerate them well. Some may experience mild water retention, tingling, or appetite changes.

How do GHRPs compare to synthetic GH?

GHRPs stimulate natural, pulsatile GH release, whereas synthetic GH produces a constant dose which can suppress the pituitary gland’s function over time. GHRPs are generally a safer, more natural approach when aiming to preserve endocrine function.

What’s the best peptide stack for growth hormone release?
Ipamorelin combined with CJC-1295 (No DAC) is commonly recommended for synergistic, pulse-like GH release.

Can GHRPs improve sleep and recovery?

Yes. GH plays a vital role in deep sleep (Stage 3 NREM), and up to 70% of daily GH secretion can occur during this phase. Many users of GHRPs report improved sleep quality, faster recovery, and more vivid dreams due to the increase in natural GH.

Are GHRPs legal and available to purchase?

GHRPs are available to purchase here for research purposes. They are not approved for therapeutic use.

What should I look for when purchasing GHRPs?

When sourcing these peptides, it’s essential to look for:

• Third-party testing for purity and consistency
• U.S.-based manufacturing standards
• Reliable delivery

DN Lab Research meets all these criteria, offering high-quality peptides backed by transparency, compliance, and efficient service.

Who should avoid using GHRPs?

People who have a history of hormone-sensitive cancers, active tumors, uncontrolled diabetes, or pregnancy should not use GHRPs unless explicitly cleared by a licensed clinician. A full consultation is essential before starting peptide therapy.

What to Know Before Purchasing

In comparison to synthetic GH, which has the potential to suppress natural GH production, GHRPs have a gentler, more physiologically aligned method to stimulate natural GH secretion. 

This supports long-term hormonal balance without halting the body’s own endocrine mechanisms.

The best choice depends on individual goals, tolerability, comorbidities, and access. 

Need help choosing the right peptide for your goals? 

Book a consultation with one of our expert peptide research specialised to get personalised guidance and support. 

Written by Elizabeth Sogeke, BSc Genetics, MPH

Elizabeth is a science and medical writer with a background in Genetics and Public Health. She holds a BSc in Genetics and a Master’s in Public Health (MPH), with a focus on mitochondrial science, metabolic health, and healthy aging. Over the past several years, she has worked with leading peptide research laboratories and functional medicine clinics, creating trusted, clinically-informed content that bridges the latest developments in peptide and longevity research with real-world applications.