CJC-1295 Side Effects and Safety: What Trials Found

What are the CJC-1295 side effects and safety risks?

CJC-1295 side effects recorded in human trials were mainly reactions at the injection site, headache, diarrhoea and flushing. Teichman's two trials reported no serious adverse reactions. Those trials were small and short. FDA, the US Food and Drug Administration, counts 63 healthy adults given the peptide across three studies. Most got one shot.

CJC-1295 is a lab-made form of GHRH. GHRH is the brain's signal to the pituitary, a small gland at the base of the brain, to release growth hormone (GH). The form studied in people carries an add-on called DAC, short for drug affinity complex. DAC lets the peptide latch onto albumin, a protein in the blood. That link is thought to explain its long life in the body.

Teichman et al. 2006 ran two trials in healthy adults aged 21 to 61. One shot raised GH 2- to 10-fold for 6 days or more. IGF-1, a growth factor GH drives, rose 1.5- to 3-fold for 9 to 11 days. The peptide's half-life, the time the body takes to clear half of it, was 5.8 to 8.1 days. The authors called it safe and relatively well tolerated, particularly at 30 or 60 micrograms per kilogram (mcg/kg) of body weight.

A second study tracked the GH rhythm. Ionescu and Frohman 2006 sampled GH overnight in healthy men aged 20 to 40, before and one week after one shot. GH still came in pulses of the same size and frequency. The level between pulses rose 7.5-fold.

Men made up most of the record. Of the 63 adults FDA's CJC-1295 review counts, 87% were men. Ionescu and Frohman studied men only.

The CJC-1295 complete guide covers what the peptide is and where it came from.

CJC-1295 side effects safety: what did the human trials find?

FDA's review lists the side effects from each trial. Teichman's first trial gave single rising doses, from 30 up to 250 mcg/kg. In it, about 70% of people given the peptide had injection-site reactions. Headache affected 63%, against 14% on placebo, a dummy shot.

Dose mattered. In the first trial, all side effects except hive-like rashes were more common at 125 or 250 mcg/kg. In the second trial, flushing came within 30 minutes of a shot and cleared within 1 to 2 hours. It followed 40% of low-dose shots and 100% of high-dose shots.

Teichman's trials found no consistent change in blood glucose, liver tests or ECGs, which are heart tracings. In the first trial, IGF-1 went above the normal range for age and sex only at the top dose, 250 mcg/kg. The CJC-1295 DAC vs no-DAC dosage page sets out every dose these studies used.

One death is on the record. A Phase 2 trial of the peptide in 192 people with HIV lipodystrophy was stopped. Lipodystrophy is a problem with where the body stores fat, seen in HIV. Phase 2 is the stage that tests whether a drug works in patients. A participant reported chest discomfort two hours after an 11th weekly dose. A heart tracing confirmed a heart attack, and the participant died about an hour later. The doctor in charge thought the most likely cause was heart artery disease that had caused no symptoms. FDA calls these reports anecdotal and says the trial data have not been published.

Does CJC-1295 cause water retention?

The two main CJC-1295 trial papers do not report it in their summaries. Neither Teichman's nor Ionescu's lists water retention as a finding.

Water retention is a known effect of GH itself. A 2007 review pooled trials that gave GH to healthy older adults, with a mean age of 69 (Liu et al. 2007). People on GH were more likely to get soft tissue swelling, called oedema. They were also more likely to get joint pain and gynecomastia, which is breast tissue growth in men.

FDA says CJC-1295 works by raising the body's own GH. So its safety profile may be expected to look like that of approved GH drugs, FDA says. The published trial summaries do not show whether CJC-1295 causes it.

What about tingling or numbness in the hands?

The same GH review found more carpal tunnel syndrome in people given GH. Carpal tunnel is a narrow channel in the wrist. Pressure on the nerve running through it causes tingling or numbness in the hand. Neither CJC-1295 trial abstract reports it.

Does CJC-1295 affect blood sugar?

Short trials saw no clear sign. Teichman's trials found no consistent change in blood glucose. They lasted 28 and 49 days, and no one got a dose after day 14.

Related drugs raise the question. Sigalos and Pastuszak 2018 reviewed drugs that prompt the body to release its own GH. Their review looked at GH-releasing peptides and ibutamoren, a pill. It did not cover CJC-1295. They found these drugs well tolerated, with some concern for higher blood sugar. The cause was lower insulin sensitivity, meaning the body responds less to insulin.

Sigalos and Pastuszak note that GH itself works against insulin's action. In Liu's review, people given GH were somewhat more likely to get diabetes or high fasting blood sugar. FDA notes that every approved GH drug label warns of poor blood sugar control and diabetes. It found no data to show CJC-1295 is free of those risks.

Does CJC-1295 raise cancer risk through IGF-1?

No study has measured it. FDA found no long-term cancer studies in animals for any form of CJC-1295.

Every approved GH drug label warns of a higher risk of neoplasm, meaning new abnormal growths such as tumours. FDA found nothing to suggest CJC-1295 is free of that risk. In mouse pituitary cells, and in live mice, the DAC form caused DNA damage, FDA reports. With no long-term studies, FDA says pituitary overgrowth or tumours cannot be ruled out.

IGF-1 plays a part in several steps of how cancer starts, per Larsson et al. 2020. That study used 416 gene variants tied to IGF-1 levels. People whose genes predict higher IGF-1 had more colorectal (bowel) cancer. For prostate, breast and other cancers, the link was unclear or absent.

Acromegaly offers human data on long-term GH and IGF-1 excess. It is a rare hormone disease. Xiao et al. 2023 pooled 19 studies of it. Overall, cancer was about 1.45 times as common in acromegaly as in the general population. Rates were higher for thyroid, colorectal, brain, stomach, urinary, blood, pancreas and small intestine, and connective tissue cancers. Breast, prostate, liver and bile duct, lung and airway, reproductive and skin cancers showed no link.

Exposure is what counted. Freda et al. 2025 followed 598 people with acromegaly. Total exposure to IGF-1 excess over time predicted cancer. The authors note that earlier work found single hormone levels did not track cancer risk. The authors say risk relates to how high IGF-1 runs and for how long.

The CJC-1295 trials raised IGF-1 1.5- to 3-fold for days to weeks. The acromegaly studies looked at excess over many years. No study has tested what longer CJC-1295 use does to cancer risk. Sigalos and Pastuszak called for long-term safety studies of related drugs, including cancer rates.

CJC-1295 side effects, risks, safety: what changes when it is stacked?

Nobody knows, because the pair has not been tested in people. No published study has given CJC-1295 together with ipamorelin, another peptide that raises GH, to people. A 2026 review found only mouse studies of the pair (Mayfield et al. 2026). FDA found the two sold online as blends.

Ipamorelin has its own safety record. In a trial of ipamorelin given by vein after bowel surgery, reviewed by FDA, two patients on the drug died. FDA says it is unclear whether the drug played a part. Low potassium hit 12.5% on ipamorelin against 3.4% on placebo. High blood sugar at discharge hit 14.3% against 8.6% (FDA ipamorelin review).

What is known about the pair is on our CJC-1295 ipamorelin stack page. Two more pages weigh up other peptides that raise GH: tesamorelin vs ipamorelin and tesamorelin vs sermorelin.

Are there CJC 1295 negative side effects we do not know yet?

The record is too thin to rule them out. Of the 63 adults FDA counts, 73% got a single shot. The longest published trial lasted 49 days.

CJC-1295 is not an FDA-approved drug. FDA once put it in category 2 of its compounding list. That group is for ingredients that may carry significant safety risks. Its safety page now lists it as a nomination that was withdrawn. The page names serious adverse events. They include a faster heart rate and vasodilatory reactions, where blood vessels widen across the body.

In December 2024, FDA's advisers voted on whether pharmacies could make it from bulk powder. They voted 0 to 13 against four of the five forms.

Is there CJC-1295 no DAC side effects safety data?

No. FDA found no study in which the form without DAC was given to people. So there is no human safety data for it. FDA also says the DAC form's drug profile cannot be carried over to the form without it.

That gap matters for what is sold. FDA found CJC-1295 and ipamorelin blends sold online for research use. For some of these blends FDA lists the CJC-1295 as the form without DAC; for others the seller does not say which form it is.

Product quality adds its own risk. FDA judged every form it reviewed not well characterised. It flagged a risk of immune reactions to the drug, from impurities and clumping, when it is injected under the skin.

A CoA is the lab report that says what is in a vial. Our guides on how to know if peptides are real and how to read a peptide CoA explain it. Our page on reliable peptide sources explains how UB reviews vendors, and our recommended sources list the result. Handling freeze-dried powder is covered in how to reconstitute peptides.

References

• Teichman SL 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
• Ionescu M, Frohman LA. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog. J Clin Endocrinol Metab. 2006. PubMed 17018654
• US Food and Drug Administration. Evaluation of CJC-1295-related bulk drug substances. 2024. FDA
• US Food and Drug Administration. Pharmacy Compounding Advisory Committee final minutes, 4 December 2024. FDA
• US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. 2026. FDA
• US Food and Drug Administration. Evaluation of ipamorelin. 2024. FDA
• Liu H et al. Systematic review: the safety and efficacy of growth hormone in the healthy elderly. Ann Intern Med. 2007. PubMed 17227934
• Sigalos JT, Pastuszak AW. The safety and efficacy of growth hormone secretagogues. Sex Med Rev. 2018. PubMed 28400207
• Larsson SC et al. Insulin-like growth factor-1 and site-specific cancers: a Mendelian randomization study. Cancer Med. 2020. PMC7520358
• Xiao Z et al. Risk of cancer in acromegaly patients: an updated meta-analysis and systematic review. PLoS One. 2023. PMC10688666
• Freda PU et al. Prospective, longitudinal study of cancer predictors and rates in a New York City cohort of 598 patients with acromegaly. J Clin Endocrinol Metab. 2025. PubMed 38986012
• Mayfield CK et al. Injectable peptide therapy: a primer for orthopaedic and sports medicine physicians. Am J Sports Med. 2026. PubMed 41476424

This content is for educational purposes only. Nothing here is a guide to research use or to treatment. Nothing here is medical advice.