peptideInjectableResearch chemicalThe only cited literature identifies this glycine-modified GRF(1-29) analog in seized doping material, not in a clinical dosing studySold in the gray market as an unregulated research chemical; not an approved drug
Modified GRF (1-29)Benefits, Dosage & Interactions
Also known as: Mod GRF, CJC-1295 no-DAC
Modified GRF (1-29), often referred to as Mod GRF or CJC-1295 no-DAC, is a synthetic peptide based on the naturally occurring growth hormone-releasing hormone (GHRH). It is a truncated analog of GHRH, specifically encompassing the first 29 amino acids of the GHRH sequence.
Researched by DoseRoutine R&D TeamReviewed for accuracy by Nicholas Alexander, RSELast updated
Evidence: Insufficient — No primary literature attached to this entry yet.
Evidence strengthInsufficient — nothing graded yet
PreclinicalStrong human evidence
No primary literature attached to this entry yet.
Plasma half-life
~30 min (estimated)
Typical timing
bedtime
Default unit
mcg
References & evidence
Documents the Modified GRF (1-29) entry is written from. Each number matches an inline marker above.
- [1]Glycine-modified growth hormone secretagogues identified in seized doping materialGajda PM, Holm NB, Hoej LJ, et al. · Drug Testing and Analysis · 2019 · Peer-reviewed · PMID 30136411
How to track Modified GRF (1-29) doses
Modified GRF (1-29) is tracked as a protocol rather than a single reminder: a vial with a concentration, a schedule that may be titrated or cycled, and a rotation of injection sites. Here is the record that keeps all three consistent.
- 1
Record the vial and concentration
Log the vial strength and the volume of bacteriostatic water you added so Modified GRF (1-29) is stored as a concentration rather than a guess. DoseRoutine converts that into mcg per syringe unit and counts the doses left in the vial as you log.
- 2
Set the schedule, not just a reminder
Enter the dose in mcg and the frequency (typical timing: bedtime). Cycled protocols get a start and end date so the history stays accurate when Modified GRF (1-29) comes out of the routine.
- 3
Rotate and log the injection site
Pick the site at the moment you log the dose. The site map shows what you used last and how recently, which is the part that drifts fastest when two compounds run on different frequencies.
- 4
Log adherence, not intentions
Mark each dose taken, skipped or delayed as it happens. Weeks of honest logs are what make an adherence rate or a trend line meaningful; retrospective guessing is not.
- 5
Review against outcomes
Review Modified GRF (1-29) alongside your logged metrics and any relevant blood work every few weeks before changing the dose, so the change is a response to data rather than to a good or bad day.
What to log each time
- Dose in mcg and the syringe units it worked out to
- Vial: reconstitution date, concentration, doses remaining
- Injection site and time
- Any side effects in the 24 h after the dose
What is Modified GRF (1-29) studied for?
What is Modified GRF (1-29)?
Modified GRF (1-29), often referred to as Mod GRF or CJC-1295 no-DAC, is a synthetic peptide based on the naturally occurring growth hormone-releasing hormone (GHRH). It is a truncated analog of GHRH, specifically encompassing the first 29 amino acids of the GHRH sequence. The 'modified' aspect refers to specific amino acid substitutions designed to enhance its stability and activity within the body compared to standard GHRH (source: PubChem). Unlike CJC-1295 with DAC (Drug Affinity Complex), Mod GRF (1-29) does not incorporate the DAC component, which significantly impacts its pharmacokinetics and half-life. Mod GRF (1-29) is typically administered via subcutaneous injection (source: reputable peptide research supply descriptions). It has been investigated for its potential to stimulate the pulsatile release of growth hormone from the pituitary gland. This stimulation is transient due to its relatively short half-life.
What does the research say about Modified GRF (1-29)?
Tap a section to expand.
Modified GRF (1-29) acts as an analog of growth hormone-releasing hormone (GHRH). Its primary mechanism involves binding to and activating the GHRH receptor on somatotroph cells within the anterior pituitary gland (source: current understanding of peptide endocrinology). This activation triggers the release of endogenous growth hormone (GH) into the bloodstream. Unlike some other growth hormone secretagogues that act on ghrelin receptors, Mod GRF (1-29) specifically targets the GHRH pathway. The modifications in its structure are intended to increase its resistance to enzymatic degradation by dipeptidyl peptidase-IV (DPP-IV), a key enzyme that rapidly inactivates native GHRH (source: scientific literature discussing peptide modifications). However, without the Drug Affinity Complex (DAC) component found in CJC-1295 with DAC, its duration of action remains short, leading to a more physiological, pulsatile release pattern of growth hormone rather than a sustained elevation (source: research papers comparing GHRH analogs). This pulsatile release mimics the natural secretion of growth hormone.
Research into Modified GRF (1-29) focuses on its potential to increase endogenous growth hormone (GH) levels, which are associated with several physiological processes. Studies in various contexts have explored its role in areas related to physical composition and recovery. The theoretical benefits stem from growth hormone's known effects on protein synthesis, lipolysis, and tissue repair (source: NIH National Institute of Diabetes and Digestive and Kidney Diseases on Growth Hormone). For example, increases in growth hormone are often linked to improvements in body composition, such as an increase in lean muscle mass and a reduction in adipose tissue (source: clinical studies on growth hormone replacement). Furthermore, growth hormone is fundamentally involved in cellular repair and regeneration, suggesting potential implications for tissue recovery following physical exertion or injury (source: review articles on growth hormone physiology). However, these observed or theoretical benefits are contingent upon the sustained elevation of GH within physiological ranges, and the short half-life of Mod GRF (1-29) means frequent administration is necessary to achieve this. The extent of these benefits in humans using Mod GRF (1-29) specifically is an ongoing area of research, with results varying based on dosage, frequency, and individual response.
Clinical evidence regarding Modified GRF (1-29) in humans is somewhat limited compared to long-standing pharmaceutical compounds. Most available information comes from research studies in animal models and human observational studies or small trials, often conducted in research or investigational settings. Studies exploring GHRH analogs, including Mod GRF (1-29), have generally shown that they can stimulate growth hormone release. For instance, some research has demonstrated that administration of GHRH analogs can lead to transient increases in circulating GH and insulin-like growth factor 1 (IGF-1) levels in healthy adults (source: scientific publications indexed in PubMed). These increases are typically short-lived due to the peptide’s rapid degradation and elimination. There is less robust, peer-reviewed evidence specifically detailing the long-term clinical outcomes of Mod GRF (1-29) use, particularly concerning improvements in muscle mass gains, fat loss, or recovery in healthy individuals. While some studies on GHRH analogs hint at these outcomes, robust large-scale clinical trials specifically on Mod GRF (1-29) for these indications are less common in established medical literature. The bulk of information available points to its established mechanism of stimulating GH release rather than its direct efficacy in achieving specific body composition or recovery goals in human populations (source: review articles on growth hormone secretagogues). Individuals considering its use often rely on anecdotal reports and data from non-clinical contexts.
As with any peptide or exogenous substance, Modified GRF (1-29) may be associated with potential side effects. The most commonly reported side effects relate to the site of injection, including redness, itching, pain, or swelling (source: common reports from peptide research forums and limited clinical observations of injectable peptides). Systemic side effects, while less frequently reported with Mod GRF (1-29) due to its short half-life, could theoretically include symptoms related to increased growth hormone (GH) levels, such as flushing, headaches, dizziness, or nausea. Some individuals may experience temporary water retention (source: general knowledge of GH effects). Changes in appetite or fatigue have also been reported by some users. Due to its impact on growth hormone release, there is a theoretical concern for altered glucose metabolism, though this would typically be more pronounced with sustained and significant elevations in GH (source: endocrine textbooks). Any persistent or concerning side effects should be reported to a healthcare professional immediately. This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Individuals considering Modified GRF (1-29) should be aware of several important warnings. As an injectable peptide, proper sterile technique is crucial to prevent local infection and other complications at the injection site (source: general medical guidelines for subcutaneous injections). Individuals with pre-existing medical conditions, particularly those involving the pituitary gland, endocrine system disorders, or malignancies, should exercise extreme caution and should not use this compound without explicit medical guidance. The impact of Mod GRF (1-29) on existing tumors or pre-cancerous conditions is not well-established and could theoretically pose risks due to its growth hormone stimulating properties (source: general oncology principles regarding growth factors). Pregnant or nursing individuals should avoid its use due to insufficient safety data. Its effects on children and adolescents, whose growth plates are still open, are also not well understood and therefore its use in these populations is not advisable. Individuals with a history of heart conditions or diabetes should consult a healthcare provider due to the potential, albeit generally mild with Mod GRF (1-29), impact on metabolic parameters and fluid balance (source: general medical considerations for growth hormone modulation). This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Modified GRF (1-29) is contraindicated in individuals with known hypersensitivity to the compound or any of its excipients. It should not be used in individuals with active malignancy or a history of malignancy due to the theoretical risk of accelerating tumor growth through increased growth hormone levels (source: general oncological guidelines). Patients with untreated active pituitary tumors or other pituitary pathologies should also avoid its use (source: endocrine society guidelines on pituitary disorders). Pregnant and breastfeeding women are advised against using Modified GRF (1-29) due to the lack of safety data in these populations and the unknown effects on fetal or infant development (source: general pharmaceutical guidelines). Its use in children or adolescents is contraindicated as it could potentially interfere with normal growth and development. Individuals with severe uncontrolled diabetes should also avoid this compound due to the potential for growth hormone to influence glucose metabolism (source: general endocrinology principles). This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
When considering Modified GRF (1-29), it's important to be mindful of potential interactions with other substances. Given its mechanism of action, it should not be mixed with other growth hormone-releasing peptides or growth hormone secretagogues unless specifically directed by a clinician, as this could lead to excessive growth hormone release. While specific drug-drug interaction studies for Modified GRF (1-29) are limited in published literature, general caution is advised when combining it with medications that significantly affect blood glucose regulation, such as insulin or oral hypoglycemic agents, as growth hormone can have a counter-regulatory effect on blood sugar (source: general endocrinology knowledge). Similarly, corticosteroids, which can suppress growth hormone secretion, might dampen the effects of Mod GRF (1-29) (source: pharmacology textbooks). Individuals taking any prescription medications, over-the-counter drugs, or other supplements should always consult with a licensed healthcare professional to assess potential interactions before using Modified GRF (1-29). This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Modified GRF (1-29) has a relatively short half-life of approximately 30 minutes (source: scientific literature discussing GHRH analogs). This short duration of action means that its effects on growth hormone release are transient and pulsatile, mimicking the natural peaks and troughs of growth hormone secretion. Due to this pharmacokinetic profile, administration is often timed to coincide with natural growth hormone peaks or to maximize its effect on recovery and anabolism. A common approach seen in research settings is administration shortly before bedtime (source: common practices in peptide research). This timing aims to synchronize with the body's natural nocturnal surge in growth hormone. Another approach might involve administration at other times during the day, such as post-workout, to capitalize on growth hormone's role in recovery. The goal is often to create several pulses of growth hormone release throughout the day, rather than a continuous elevation. Regardless of timing, it is important to adhere to a consistent schedule if using this compound. Individual needs vary — talk to a licensed clinician.
What interacts with Modified GRF (1-29)?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any peptide + hormone | Note | Category ruleConfidence: theoretical | Injectable peptides plus hormones can have overlapping or compounding effects that aren't always well characterized.Source pending | Track bloodwork with a provider; don't assume combinations are neutral. |
Frequently asked questions about Modified GRF (1-29)
No, Modified GRF (1-29) is often referred to as CJC-1295 no-DAC. The key difference is the absence of the 'DAC' (Drug Affinity Complex) component. The DAC component in CJC-1295 with DAC significantly extends its half-life, leading to a prolonged and sustained release of growth hormone, whereas Modified GRF (1-29) has a much shorter half-life and results in pulsatile growth hormone release (source: scientific literature comparing GHRH analogs).
Modified GRF (1-29) is typically administered via subcutaneous injection (under the skin), similar to how insulin is injected. Proper sterile technique and injection site rotation are important to minimize discomfort and prevent complications (source: standard practices for injectable peptides).
Research into Modified GRF (1-29) focuses on its ability to stimulate the pulsatile release of endogenous growth hormone. This is theorized to support muscle development, enhance recovery, and potentially affect body fat levels, though robust clinical trial data specifically on these outcomes for Mod GRF (1-29) in humans is limited (source: review articles on GHRH analogs).
The half-life of Modified GRF (1-29) is relatively short, typically around 30 minutes. This means it is rapidly cleared from the body, leading to a transient, pulsatile release of growth hormone rather than a sustained elevation (source: peptide research studies).
No, as a peptide, Modified GRF (1-29) would be broken down and rendered ineffective by digestive enzymes if taken orally. It must be administered via injection to be effective (source: general knowledge of peptide pharmacology).
Interaction risk for Modified GRF (1-29) comes from the rest of the stack: other peptides, prescription medicines, hormone therapy and peptides. Because Modified GRF (1-29) is usually taken in the evening, most avoidable conflicts come from what else lands in that same window. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Modified GRF (1-29) with no sign-up.
Modified GRF (1-29) is typically taken in the evening. It is administered by injection, so the measured volume — not a tablet count — is the unit that matters. Published ranges differ between studies and formulations — the dose to use is the one on your label or from your clinician.
There is no single answer for Modified GRF (1-29) plus TRT. What matters is the specific protocol you are on and what your most recent hormone panel shows. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Pairing Modified GRF (1-29) with peptides has to be assessed one peptide at a time, because GLP-1 agonists, secretagogues, healing peptides and melanocortins do not share an interaction profile. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Modified GRF (1-29) varies by protocol and formulation, so the label or prescription is what sets it. It is typically taken in the evening. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Modified GRF (1-29) depends on the protocol and formulation you are on. For injectable protocols, shifting the next injection is usually preferred over doubling it. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For an injectable like Modified GRF (1-29) the record needs more than a checkbox: vial concentration, the measured volume, and which site the last injection went into. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Which studies looked at Modified GRF (1-29)?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Glycine-modified growth hormone secretagogues identified in seized doping material(opens PubMed in a new tab)Drug Test Anal · 2019 · PMID 30136411 · https://pubmed.ncbi.nlm.nih.gov/30136411/
Verify at
Publisher search links for Modified GRF (1-29). These are places to check the information — they are not citations, so they are not numbered.
- PubChem(publisher search, opens in a new tab)National Center for Biotechnology Information · publisher search
- MedlinePlus(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- Clinical practice guidelines (PubMed)(publisher search, opens in a new tab)National Library of Medicine · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Modified GRF (1-29)?
Plain-text summary, safe to quote verbatim:
Modified GRF (1-29), often referred to as Mod GRF or CJC-1295 no-DAC, is a synthetic peptide based on the naturally occurring growth hormone-releasing hormone (GHRH). It is a truncated analog of GHRH, specifically encompassing the first 29 amino acids of the GHRH sequence.
Source: DoseRoutine — https://doseroutine.com/library/modified-grf-1-29
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Modified GRF (1-29) — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/modified-grf-1-29
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Which goals is Modified GRF (1-29) used for?
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