Steroids vs. Peptides: Health Outcomes Years Later

Two kinds of evidence, years apart

The long-term health picture for anabolic-androgenic steroids (AAS) comes from people. Researchers have imaged the hearts of long-term users and followed them through national health registries for more than a decade. For peptides, the picture is mostly blank: human trials of growth hormone (GH) releasing peptides lasted days to weeks, and recovery peptides such as BPC-157 and TB-500 have almost no human data.

A 2014 Endocrine Society scientific statement points out that randomized trials can't ethically give the doses steroid users actually take, so steroid harms are measured in observational studies of real users. Nobody has run the equivalent studies for peptides. FDA's 2024 advisory committee review of CJC-1295 called its long-term safety profile in humans "unknown", and as of October 2026 no study has followed long-term peptide users alongside long-term steroid users.

The shorter list of documented peptide harms partly reflects how little anyone has looked. For sustained peptide use more broadly, see our overview of long-term health outcomes.

Heart and blood vessels

Steroids. In a 2017 Circulation study, 86 experienced weightlifters with at least two years of cumulative steroid use had a mean left ventricular ejection fraction of 52%, compared with 63% in 54 lifters who had never used. Users also had more coronary artery plaque, and plaque volume rose with lifetime years of use.

Registry data show where those changes can lead. A Danish study published in Circulation in 2025 followed 1,189 men caught using steroids in fitness-center doping controls for an average of 11 years and compared them with 59,450 matched men from the general population. After adjustment, steroid users had about three times the risk of heart attack, 3.6 times the risk of heart failure, and almost nine times the risk of cardiomyopathy. A smaller Danish study found higher 24-hour systolic blood pressure in current users (132 vs 124 mmHg) and stiffer aortas in both current and former users, which suggests some vascular changes outlast the drug.

GH-releasing peptides. No study has imaged the hearts of long-term users of ipamorelin, CJC-1295 or GHRP-2, and the short-term safety data are less clean than this page used to claim. FDA's 2024 review of the 2006 CJC-1295 trials in healthy adults lists raised heart rate, systemic vasodilatory reactions such as flushing, and transient dizziness and low blood pressure. According to anecdotal reports FDA cited, a Phase 2 trial in people with HIV lipodystrophy was stopped after a participant had a fatal heart attack two hours after his 11th weekly dose. The attending physician blamed undiagnosed coronary disease, but the data were never published, so the event can't be weighed either way. Separately, FDA's 2024 ipamorelin review said there were insufficient data to conclude it wouldn't raise the same concerns as approved products that boost GH and insulin-like growth factor 1 (IGF-1).

BPC-157. Claims that BPC-157 protects the heart come from animal studies. A 2025 systematic review in HSS Journal included 35 preclinical studies and a single clinical one, and its authors wrote that "no clinical safety data were found."

Testosterone, fertility and mood after stopping

AAS shut down the body's own testosterone production by suppressing luteinizing hormone (LH) and follicle-stimulating hormone (FSH). How fully people recover is disputed:

• Mostly reversible. A 2020 Australian study of 41 current users, 31 past users (median about 300 days off) and 21 non-users found that past users looked like non-users apart from smaller testes. LH took about 11 months on average to recover and sperm output about 14 months.
• Often prolonged. In a 2015 study of 19 untreated former long-term users, five still had testosterone below 200 ng/dL 3 to 26 months after stopping. Across all 24 former users, 29% had a major depressive episode during withdrawal.
• Lower quality of life. A 2024 Danish study of 77 former users, about two years after stopping, found lower testosterone than in controls (median 14 vs 19 nmol/L) and lower quality-of-life scores.

All three are small cross-sectional studies, and they recruited differently (one through social media, another partly from an endocrine clinic, where men with lingering problems are likelier to turn up). A fair reading: many men recover within 6 to 18 months, and a real minority don't. The depression finding connects to our article on psychological support for bodybuilders.

Peptides. GH secretagogues act on the ghrelin receptor or the GHRH receptor in the pituitary, not on the androgen receptor, so they have no known mechanism for the direct testosterone shutdown AAS cause. Community guides commonly say no post-cycle therapy is needed, and the short trials didn't report suppression, but no study has measured testosterone or fertility in people using these peptides for months or years. The longest trial we found for this drug class, a two-year study of the oral GH secretagogue MK-677 in older adults, did find that cortisol rose. For BPC-157 and TB-500 there are no human hormone data at all. Our guide to peptide cycling strategies covers how users plan time off.

Kidneys and liver

Steroids. A 2010 case series from Columbia University described 10 bodybuilders with kidney disease after long-term steroid use; nine had focal segmental glomerulosclerosis (FSGS) on biopsy. Of eight followed for about two years, one reached end-stage kidney disease. In the others, stopping steroids stabilized or improved kidney function, and one man who restarted relapsed. The authors suspect the problem is underrecognized because high muscle mass already pushes creatinine up.

Liver injury is the older, better-known risk. A 2020 review in BMJ Open Gastroenterology pooled 52 cases of steroid-related liver injury, most often from methyldrostanolone. Patients usually showed up with jaundice about eight weeks after starting, and 43% also had kidney injury. None died or needed a transplant.

Peptides. According to the 2025 HSS Journal review, BPC-157 is broken down in the liver and cleared by the kidneys, with a half-life under 30 minutes, and preclinical safety studies found no organ damage. Nobody has checked kidney or liver function in long-term human users. The lack of case reports linking peptides to kidney failure isn't evidence of safety, since far fewer people use them and no one collects reports systematically. Product quality is its own risk: FDA warns that compounded peptides can carry impurities and provoke immune reactions, and the HSS review authors flag contamination from unregulated manufacturing.

Blood sugar: the clearest peptide signal

The most consistent long-term warning for GH-raising compounds involves glucose. In the two-year MK-677 trial (25 mg by mouth daily, in 65 adults aged 60 to 81), fasting glucose rose by about 5 mg/dL and insulin sensitivity fell. Lean mass went up by about 1.1 kg, but strength and function didn't change. MK-677 isn't a peptide, but it acts on the same ghrelin receptor as ipamorelin and GHRP-2, which makes it the best long-term proxy available. In a Phase 2 trial of IV ipamorelin after bowel surgery, the ipamorelin group had more high blood sugar, low potassium and insomnia at discharge. Two people in that group died after treatment ended, and FDA said causality wasn't clear.

Not every study shows the glucose effect. In 11 men aged 64 to 76, six weeks of nightly sermorelin injections (2 mg) didn't change glucose, insulin, lipids or body composition, and the researchers saw no significant side effects. That study was small and short. On lipids, the MK-677 trial found LDL slightly lower and HDL unchanged, while current steroid users in the 2020 Australian study had worse lipoprotein profiles than past users or non-users.

What users report

Users of GH-releasing peptides commonly describe water retention, tingling or numb hands, flushing and tiredness. BPC-157 users mostly mention injection-site irritation and, less often, fatigue or low mood in the first week. Most say these fade, which fits the short-trial data. What user reports can't show is what happens to blood sugar or heart structure over years, because those changes are silent until bloodwork or imaging finds them. Many lifters also combine peptides with steroids, so a long-term problem can't be pinned on either one. Useful bloodwork depends on telling a doctor what's being used, which our article on talking to your doctor about peptides covers.

Where the evidence stands

What we still don't know

• Whether months or years of GH-releasing peptides raise diabetes risk the way the MK-677 data hint. No trial in the class has run past two years.
• Whether long-term peptide use affects testosterone, sperm or fertility. It hasn't been measured.
• What sustained IGF-1 elevation means for cancer and heart risk in healthy adults. FDA's 2024 reviews flag risks tied to raised GH and IGF-1 in general, but there are no outcome data.
• As of October 2026, a randomized, placebo-controlled pilot trial of BPC-157 (about 30 patients after rotator cuff surgery, University of Arkansas) is listed as not yet recruiting, with a planned start in January 2027. It will collect safety data over 90 days, not years.