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Comparison

Mod GRF 1-29 vs Sermorelin

Both are GHRH analogs, so the meaningful differences are in kinetics, evidence and regulatory status.

On published evidence alone, Sermorelin is the better documented of the two (regulator approved). That is a statement about the state of the literature, not a recommendation.

Mod GRF 1-29 Sermorelin
Class GHRH analogs GHRH analogs
Evidence Preliminary human Regulator approved
Human trials ~4 ~20
Half-life ~30 minutes ~10-20 minutes
Reported range 100-300 mcg 200-500 mcg
Frequency 1-3x daily Once daily at bedtime
Routes Subcutaneous Subcutaneous
FDA approved No Yes
Research use only Yes No
Banned in sport Yes Yes
Studied for Growth hormone elevation, Stacking with GHRPs Growth hormone deficiency diagnosis and paediatric treatment, Age-related GH decline, Sleep quality, Body composition
Reported side effects Injection-site reactions, Flushing, Water retention Injection-site erythema, Flushing, Headache, Transient dizziness

Mod GRF 1-29

Mod GRF 1-29 and CJC-1295 without DAC refer to the same tetrasubstituted GHRH(1-29) sequence. The duplicate naming arose from research-chemical labelling rather than from any pharmacological difference, and it is the most common reason buyers receive a product with different kinetics than they intended. The practical risk is confusing this short-acting peptide with the DAC-bound version, whose dosing is an order of magnitude different and weekly rather than daily.

Sermorelin

Sermorelin is a truncated analog of growth-hormone-releasing hormone comprising residues 1-29, the minimum sequence required for receptor activation. It binds the GHRH receptor on anterior pituitary somatotrophs and stimulates synthesis and pulsatile release of endogenous growth hormone. Because it acts upstream on the pituitary rather than replacing growth hormone directly, release remains subject to negative feedback from somatostatin and IGF-1, which is the usual argument for a lower risk of supraphysiologic exposure than exogenous hGH.

Mod GRF 1-29 vs Sermorelin: common questions

What is the difference between Mod GRF 1-29 and Sermorelin?

Both are GHRH analogs. Mod GRF 1-29: A naming convention for the non-DAC tetrasubstituted GHRH(1-29) analog, used interchangeably with CJC-1295 without DAC and a frequent source of dosing confusion. Sermorelin: The first 29 amino acids of endogenous growth-hormone-releasing hormone, and the shortest fragment that retains full biological activity.

Which has stronger evidence, Mod GRF 1-29 or Sermorelin?

Sermorelin has the stronger evidence base (regulator approved, about 20 human studies) compared with Mod GRF 1-29 (preliminary human).

Are Mod GRF 1-29 and Sermorelin FDA approved?

Only Sermorelin is FDA approved (Diagnostic assessment of pituitary GH secretory capacity (Geref); Treatment of idiopathic growth hormone deficiency in children with growth failure (Geref, approved 1997; discontinued by the manufacturer in 2008, not for safety reasons)). Mod GRF 1-29 is not approved for any indication.

References

Regulatory and primary sources

  1. WADA Prohibited List ↗ · current year
  2. FDA: Unapproved drugs and "research use only" products ↗ · regulatory status of non-approved products
  3. PubChem compound record (CID 16132413) ↗ · structure, identifiers, synonyms
  4. DailyMed: FDA-approved labeling for Sermorelin ↗ · indications, dosing, warnings as approved
  5. FDA Drugs@FDA database ↗ · approval history
  6. CAS Registry Number 86168-78-7 ↗ · chemical identity

Published literature

  1. Mayfield CK, Bolia IK, Feingold CL, et al.. Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.Am J Sports Med 2026.PubMed 41476424 · doi:10.1177/03635465251357593
  2. Teichman SL, Neale A, Lawrence B, et al.. Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults.J Clin Endocrinol Metab 2006.PubMed 16352683 · doi:10.1210/jc.2005-1536
  3. Rahman OF, Lee SJ, Seeds WA. Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.J Am Acad Orthop Surg Glob Res Rev 2026.PubMed 41490200 · doi:10.5435/JAAOSGlobal-D-25-00236
  4. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.Sports Med 2026.PubMed 41966639 · doi:10.1007/s40279-026-02437-0
  5. Renke G, Chinellato L. Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives.Int J Mol Sci 2026.PubMed 42123471 · doi:10.3390/ijms27093890
  6. Coutinho LFD, DE Oliveira Neves LF, Camilo RP. A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review.J Sports Med Phys Fitness 2026.PubMed 41880199 · doi:10.23736/S0022-4707.26.17773-1
  7. Van Hout MC, Hearne E. Netnography of Female Use of the Synthetic Growth Hormone CJC-1295: Pulses and Potions.Subst Use Misuse 2016.PubMed 26771670 · doi:10.3109/10826084.2015.1082595
  8. Thomas A, Schänzer W, Delahaut P, et al.. Immunoaffinity purification of peptide hormones prior to liquid chromatography-mass spectrometry in doping controls.Methods 2012.PubMed 21871962 · doi:10.1016/j.ymeth.2011.08.009
  9. Memdouh S, Gavrilović I, Ng K, et al.. Advances in the detection of growth hormone releasing hormone synthetic analogs.Drug Test Anal 2021.PubMed 34665524 · doi:10.1002/dta.3183
  10. Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?.Clin Interv Aging 2006.PubMed 18046908 · doi:10.2147/ciia.2006.1.4.307
  11. Ramirez G, Herrera R, Pineda D, et al.. The effects of high altitude on hypothalamic-pituitary secretory dynamics in men.Clin Endocrinol (Oxf) 1995.PubMed 7641401 · doi:10.1111/j.1365-2265.1995.tb01887.x
  12. Popovic V, Pekic S, Golubicic I, et al.. The impact of cranial irradiation on GH responsiveness to GHRH plus GH-releasing peptide-6.J Clin Endocrinol Metab 2002.PubMed 11994347 · doi:10.1210/jcem.87.5.8485
  13. Saenger P, Pescovitz OH, Bercu BB, et al.. Outcome of growth hormone therapy in children with growth hormone deficiency showing an inadequate response to growth hormone-releasing hormone.Endocrine 2001.PubMed 11572326 · doi:10.1385/ENDO:15:1:051

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.