MOD GRF 1-29 Complete Profile, Dosage & Usage



Molecular Formula


Molecular Weight

3367.954 g/mol

PubChem CID


What is MOD GRF 1-29?

MOD GRF 1 Vial

Mod GRF (1-29), also known as Modified GRF (1-29) or tetrasubstituted GRF (1-29), is an injectable peptide used to boost growth hormone (GH) production. This peptide is a modified version of Growth Hormone Releasing Factor (1-29), in which four amino acids located in positions 2, 8, 15, and 27 of the amino acid chain have been replaced with more stable amino acids that are resistant to enzymatic cleavage. GHRH and ghrelin are two primary regulators of GH secretion in humans and both have been extensively studied in drug development. However, GHRH alone is not an ideal therapeutic agent due to its short duration of action. Mod GRF 1-29 is a more viable alternative as it has a longer half-life and is more potent in increasing serum GH and IGF-1 levels..

Mechanism of Action

Modified GRF 1-29 operates by binding to growth hormone releasing hormone receptors (GHRHr) in the anterior pituitary gland, akin to the body's natural GHRH. By enhancing the pulsatile release of growth hormone, it promotes the production of IGF-1. For optimum effectiveness, Modified GRF 1-29 should be administered in synchrony with the body's natural growth hormone release or in conjunction with a GHRP to further augment the peptides' efficacy. The positive impact of Modified GRF 1-29 on growth hormone output, like that of GHRH, is governed by a negative feedback mechanism initiated by somatostatin, also known as growth hormone inhibiting hormone (GHIH). This mechanism averts excessive and unhealthy growth hormone levels while enabling natural patterns of fluctuation in growth hormone concentrations, thereby minimizing the undesirable side effects that typically accompany artificial hGH administration.

Pharmacological class of Mod GRF 1-29

Mod GRF 1-29 belongs to the pharmacological category of growth hormone releasing hormone (GHRH) mimetics, which mimic the natural hormone GHRH. However, GHRH is not commonly used in bodybuilding or as a performance-enhancing drug due to its high cost of production and short duration of action. Mod GRF is a modified version of the first 29 amino acids of GHRH and has a more stable form that remains active in the body for a useful duration of time.

Like GHRH, Mod GRF works by increasing the production of growth hormone (GH). However, it does not initiate a pulse of GH release when administered alone. Instead, it can only enhance GH release if administered during a natural pulse. Therefore, if there is no natural pulse at the time of injection, Mod GRF will not be effective.

When to use?

A moderate dose GH cycle can be substituted with Mod GRF 1-29, especially for those who wish to stimulate their own GH production rather than having it replaced with injectable GH. It can also be used in conjunction with anabolic steroids to enhance muscle growth and reduce fat. Other potential advantages include enhanced skin aesthetics and faster wound healing.

Mod GRF 1-29 can be used continuously without needing to cycle; it is best taken at the lower end of the dosage range or once daily, just before bed, at full strength.

However, overusing GH-stimulating peptides can have negative side effects, including impaired insulin sensitivity, painful nerve compression, and excessive water retention. In such cases, it is best to discontinue use and reduce dosage until the issue is resolved.


Modified GRF 1-29 is commonly administered via subcutaneous injection into a fleshy body area, such as the stomach or abdominal region. It's crucial to adhere to the following guidelines before injecting:

  • Use a clean, sterilised syringe
  • The syringe should be put into the centre of the cap while the bottle is held upright. 
  • After accurately measuring the dosage, carefully remove the syringe. 
  • Pinch the skin around the injection site, leaving about 2 cm on either side, then wipe the region of the skin with alcohol before giving the injection. 
  • Quickly enter the syringe while maintaining a 90-degree angle with the skin. 
  • When the syringe is empty, fully depress the plunger before carefully removing it.


Dosage Amount:100mcg (0.1mg)

Dosage Frequency:1 - 3 times daily

The recommended dosage for Mod GRF 1-29 is 100 mcg, which can be administered once daily before bedtime. This dosing protocol can lead to a gradual but significant increase in growth hormone production over time, while still following the natural patterns of growth hormone release.

For those looking to enhance strength and performance, a higher dosage of 100mcg can be administered three times a day, in combination with a GHRP peptide. This peptide stack can generate a substantial increase in growth hormone output, thereby facilitating muscle growth, fat loss, and recovery from training and injury. However, it is important to note that using a higher dosage should be done with caution and only under the guidance of a healthcare professional.

Side Effects

Typically, the side effects of Modified GRF 1-29 are mild and depend on the dosage, with negative effects being rare at moderate levels. Upon initial injection, mild symptoms such as skin flushing, nausea, stomach upset, dizziness, and headaches may occur. These symptoms usually decrease with repeated injections. It is also possible to experience tiredness or lethargy, as growth hormones can enhance the desire for quality sleep and promote restorative capabilities.

Overdosing on Modified GRF 1-29 can cause tingling or numbness in the hands and feet, and water retention may indicate that the dosage should be lowered. If any negative side effects are suspected, it is recommended to immediately discontinue use and seek medical attention.


There are many benefits of MOD GRF 1-29 peptide. Primarily, this peptide is known for increasing natural growth hormone production, promoting fat loss, increasing muscle mass, and improving overall wellness, as research on animals has shown.

Due to its role in increasing GH production, MOD GRF 1-29 results include greater muscle and lean body mass as well as enhanced recovery from injuries, studies have shown.

  • Increase in muscle growth and lean body mass
  • Acceleration of wound healing from injury or training
  • Enhancement of fat burning and weight loss
  • Improvement in bone growth
  • Increase metabolism
  • Improvement of the immune system and blood sugar regulation
  • Enhancement of flexibility and joint health
  • Improvement of quality of sleep and rest
  • Increase in energy, vitality and overall wellness

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