At a glance
Effects
- GH Pulse Amplification: Binds pituitary GHRH receptors to trigger discrete, pulsatile GH release events, more closely mirroring natural GH rhythm than continuous exogenous GH [3].
- Lean Muscle Support: Elevated GH and downstream IGF-1 promote protein synthesis, muscle cell growth and repair, and lean mass accrual over time [5][6].
- Fat Metabolism: Raised GH levels shift the body toward fat oxidation, contributing to reduced body fat and improved body composition [6].
- Recovery & Tissue Repair: GH and IGF-1 accelerate cellular regeneration, improving recovery from training and potentially supporting connective tissue and joint health [4].
- Sleep Quality: Pulsatile GH release is naturally highest during deep sleep; pre-bed dosing may support deeper, more restorative sleep [4].
GHRH analogue / Growth hormone secretagogue (GHS)
~30 minutes (subcutaneous)
Subcutaneous injection (primary); IM or IV also reported
Not FDA-approved for human use; research chemical in the US; prescription-only in UK & Canada
GH pulse within minutes of injection; peaks and clears rapidly
About mod GRF (1-29)
Every point here is drawn from public medical and harm-reduction sources. A bracketed number after a claim — like [1]— is a reference: tap it to open the exact source it's based on (numbered list at the bottom). It is not a rating or score. Educational information, not medical advice.
Product specifics
- Est. delivery
- 3–7 business days · EU tracked
Product details as stated by the vendor (claims, not independently verified). Delivery is our standard EU estimate.
What it is
Mod GRF (1-29) — also known as Modified GRF (1-29), tetrasubstituted GRF (1-29), or CJC-1295 without DAC — is a synthetic 29-amino acid analogue of human Growth Hormone-Releasing Hormone (GHRH), engineered for enhanced enzymatic stability [1]. It is used as a growth hormone secretagogue: it signals the pituitary gland to release endogenous growth hormone in pulsatile bursts, and is sought for performance, recovery, body-composition, and anti-ageing purposes [6].
How it works
Mod GRF (1-29) binds to GHRH receptors on somatotroph cells in the anterior pituitary gland, triggering the release of endogenous growth hormone in brief, pulsatile bursts that closely mimic the body's own natural GH secretion rhythm [3]. Four targeted amino acid substitutions (at positions 2, 8, 15, and 27) confer strong resistance to DPP-4 and other plasma proteases, extending the effective half-life from the sub-10-minute window of native GRF (1-29) to approximately 30 minutes [2]. Because its effects are modulated by somatostatin — the body's own GH-inhibiting hormone — the risk of extreme, supraphysiological GH levels is theoretically lower than with exogenous recombinant GH [4]. Elevated GH subsequently stimulates the liver to produce IGF-1, which drives downstream anabolic and recovery effects [5].
Risks & side effects
Most important: Because Mod GRF (1-29) raises IGF-1 levels, it must not be used by anyone with a personal history of cancer or active hormone-sensitive tumours, as elevated IGF-1 may promote proliferation of malignant cells [7]. No significant long-term human clinical trials exist specifically for standalone Mod GRF (1-29), so the full long-term safety profile — including proliferative risk — remains incompletely characterised [8].
Common
Serious
- Elevated IGF-1 — sustained supraphysiological IGF-1 may carry proliferative risk; periodic blood monitoring required [9]
- Transient hypotension following injection [10]
- Tingling or numbness in hands and feet at excessive doses [4]
- Purity / contamination risk from unregulated research-chemical sources — concentration variance and occasional contaminants reported in third-party testing [13]
Safety & harm reduction
- Personal history of cancer or active malignancy — elevated IGF-1 may promote tumour growth [7]
- Active pituitary pathology or known GH-secreting tumours [9]
- Untreated hypothyroidism or uncontrolled endocrine disorders [9]
- Pregnancy or breastfeeding — no safety data available
- Children and adolescents — pituitary axis not fully mature
- Baseline and periodic serum IGF-1 — primary surrogate marker for cumulative GH activity; adjust protocol if above age/sex-adjusted reference range [9]
- Baseline endocrine workup including fasting GH and IGF-1 before starting [9]
- Monitor body composition, energy levels, and subjective well-being for signs of over-response [8]
- Watch for oedema (water retention) as a dose-too-high signal [4]
- GHRP agents (Ipamorelin, GHRP-2, GHRP-6) — synergistic amplification of GH pulse; combination widely used but increases overall GH/IGF-1 elevation and side-effect potential [12]
- Insulin / glucose-lowering drugs — GH is counter-regulatory to insulin; monitor blood glucose, especially in diabetic patients
- Glucocorticoids (e.g. prednisone) — may blunt GH response
- Exogenous recombinant GH — additive GH elevation; co-use increases supraphysiological risk
- Reconstitute lyophilised powder with bacteriostatic water; common ratio is 2 ml per 2 mg vial [11]
- Store lyophilised vials at -20 °C long-term; once reconstituted, refrigerate and use within 30 days [14]
- Rotate injection sites to reduce localised reactions [5]
- Inject on an empty stomach (fasting state) or post-workout to maximise GH pulse amplitude — food and elevated insulin suppress GH release
- Cycle use and include periodic breaks; consult a physician before starting and during use [8]
Dosage context
Commonly reported in community and vendor sources (not a prescription): 100 mcg per injection, administered 1–3 times daily, often timed pre-bed and/or post-workout [11]. Dosing should always be individualised based on body weight, goals, and tolerance under clinical guidance. These figures are educational context only — no large-scale human clinical trials specifically for standalone Mod GRF (1-29) have established an evidence-based optimal dose [8].
Sources
- 1.Biotech Peptides — Mod GRF 1-29 product & amino acid substitution overview
- 2.Peptides Lab UK — CJC-1295 Without DAC technical profile
- 3.Jay Campbell — Mod GRF 1-29 vs CJC-1295: What's the Difference?
- 4.Peptide Guide — Modified GRF 1-29 (link unavailable)
- 5.Muscle and Brawn — Mod GRF 1-29 Summary
- 6.The Peptide Report — Mod GRF 1-29/Ipamorelin Dosage
- 7.Healthcare Business Today — Safety and Efficacy of Mod GRF 1-29
- 8.Jay Campbell — Mod GRF 1-29 Peptide Benefits for Beginners
- 9.Newtropin — MOD GRF 1-29: Mechanism & Endocrine Signaling
- 10.Arenis Medico — Mod GRF 1-29 product profile
- 11.Peptide Calc App — MOD-GRF (1-29) Dosage, Half-Life & Side Effects (2026)
- 12.Platinum Research Compounds — Mod GRF 1-29 Growth Hormone Optimisation (link unavailable)
- 13.FormBlends — Ipamorelin Side Effects: Complete Safety Profile
- 14.HLExtract — CJC-1295 with DAC vs. Without DAC: Technical Comparison
- 15.FDA Regulations.gov — CJC-1295 / Modified GRF (1-29) regulatory document
- 16.Superpower.com — CJC-1295: A Long-Acting GHRH Analog
- 17.BOC Sciences — What is CJC-1295 without DAC?
This information is provided for educational and harm-reduction purposes only. It is not medical advice. These substances can carry serious health risks; effects and safe use vary by individual. Consult a qualified healthcare professional before use. Legal status varies by country — it is your responsibility to know your local law. We do not encourage misuse.
Other options for mod GRF (1-29)· 3 offers
Same compound from different labs/brands and pack sizes. Tap a row to switch brand — the price and buy button update instantly.
| Brand | Form | Strength | Pack | Price | Per mg |
|---|---|---|---|---|---|
Generic | vial | 10 mg | 10 vial | 179,99 € | — |
GenericSelected | vial | 5 mg | 10 vial | 299,99 € | — |
Generic | vial | 2 mg | 10 vial | 429,99 € | — |