Peptides for Longevity

These short chains of amino acids do possess legitimate biological activity—several peptides serve as medications approved by the United States Food and Drug Administration (FDA) for specific conditions—but there is a vast gap between sanctioned medical uses and the sweeping wellness claims online.

Most so-called anti-aging peptides generating attention are unapproved compounds sold online as "research peptides," including BPC-157, CJC-1295, and TB-500. Many lack robust human data, sitting in a regulatory gray—and sometimes red—zone. This calls for skepticism and a good amount of caution.

What are peptides?

Peptides are short chains of amino acids that can act like mini hormones or signaling molecules. Several have established medical uses: GLP-1s for diabetes and obesity; parathyroid analogs for osteoporosis; oxytocin for inducing labor; desmopressin for diabetes insipidus; and tesamorelin for HIV-associated lipodystrophy.

The compounds driving longevity discussions, however, are different entirely.
BPC-157, CJC-1295, epitalon, semorelin, ipamorelin, LL-37, TB-500 (a thymosin-β4 fragment/derivative), and similar substances are sold online as “research peptides” without FDA approval for human use. Despite extensive marketing around their potential benefits, none of these peptides have been proven effective as anti-aging therapies in rigorous human studies.

What the evidence shows

The appeal of peptides for longevity stems from several factors that create a compelling—if misleading—narrative. Proponents emphasize how naturally occurring peptides function as essential biological messengers. They also often highlight the extensive list of FDA-approved peptides for various medical conditions, and present detailed data from laboratory and animal studies. However, the truth is considerably murkier.

• Many popular “longevity” peptides work by boosting growth hormone production, yet animal studies consistently show that lower—not higher—growth hormone and IGF-1 levels are associated with longer lifespans.
• For most “longevity” peptides, long-term randomized evidence on healthspan or lifespan in humans is absent. A handful show benefits in specific medical conditions—such as tesamorelin for visceral fat accumulation in HIV and GLP-1s in type 2 diabetes, obesity, and heart disease—but extrapolating these findings to general anti-aging applications lacks scientific support.
• For popular “wellness” peptides, such as BPC-157, CJC-1295/ipamorelin, and TB-500, there are no high‑quality, long‑term human studies demonstrating improved healthspan or survival and there are significant potential adverse events.
• Thymosin-α1 (Tα1; thymalfasin) is a peptide that has been studied in multiple randomized controlled trials and a recent meta-analysis for sepsis suggested improved immune function and potential survival benefits, but more recent large randomized controlled trial data have not confirmed a clear mortality benefit, so the role of Tα1 in sepsis remains uncertain. While Tα1 isn't FDA-approved in the U.S., thymalfasin is approved and regulated for therapeutic use in over 35 countries—mainly for chronic viral hepatitis and immune enhancement during chemotherapy or as a vaccine booster.
• Pro-healing peptides like thymosin-β4 derivatives have shown promise in lab studies for wound repair and tissue regeneration, but translating these findings to lasting clinical outcomes in patients remains limited.
• The body’s natural production of antimicrobial peptides like LL-37 is tightly controlled. Excessive amounts can promote inflammation, contribute to autoimmune disease, or induce antimicrobial resistance. This reinforces the need to study doses higher than what the body naturally produces for all of these substances.

The regulatory status in the U.S.

Many peptides marketed online are unapproved drugs and the FDA has issued warning letters to vendors selling peptides labeled as “research compounds” that are intended for human use.

The FDA flags numerous peptide bulk substances as potential safety risks, including BPC-157, LL-37, DSIP, epitalon, injectable GHK-Cu, and thymosin-β4 fragment, where concerns about impurities, immune reactions, proper characterization, or adverse events have been cited. Others, such as CJC-1295 and ipamorelin, are separately flagged by the FDA with reported serious events.

In competitive sports, the World Anti-Doping Agency prohibits many peptides, including CJC-1295 and ipamorelin, as growth-hormone secretagogues—compounds that cause growth hormone to be released. Beyond athletics sanctions, this prohibition signals that these compounds can meaningfully alter physiology and therefore carry risk.

What we know about the most popular “longevity” peptides

1. Tesamorelin

Claims: Anti-aging benefits, general weight loss/body composition improvement, and longevity enhancement

Evidence: It is FDA-approved for reducing excess abdominal fat in people with HIV-associated lipodystrophy, a rare disorder that causes abnormal fat distribution. In people with HIV, randomized controlled trials show reductions in visceral fat tissue and improvements in liver fat, with slower progression of liver scarring in subgroups with fatty liver disease.

The FDA label warns about elevated IGF-1, fluid retention, glucose intolerance, potential cancer risks, and unknown long-term cardiovascular effects.

2. BPC‑157

Claims: Tendon, ligament, and gut healing.

Evidence: The data is mainly animal studies with no robust human randomized controlled trials. One small pilot study in 2025 primarily reported short-term tolerability, which falls far short of proving effectiveness. The U.S. Department of Defense’s Operation Supplement Safety and the U.S. Anti-Doping Agency classifies BPC-157 as an unapproved drug and prohibited substance for athletes. It is not FDA-approved. Regulators also warn that compounded and unauthorized peptide products containing BPC-157 may pose serious health risks; human safety data for BPC-157 itself are extremely limited, and no safe, evidence-based dosing has been established.

BPC-157 is increasingly being marketed in oral capsules online, but these are not FDA-approved formulations and lack sound clinical data supporting their use. Reports include serious adverse events.

3. TB-500 (thymosin-β4 fragment/derivative)

Claims: TB-500 is marketed for systemic wound healing and tissue regeneration throughout the body.

Evidence: While laboratory and animal studies show strong results, there is limited clinical evidence demonstrating benefits for musculoskeletal health or athletic performance in humans.

The compound remains unapproved in the U.S. and is prohibited for use in competitive sports.

What about GLP-1s?

GLP-1 receptor agonists like semaglutide are peptide drugs with strong randomized trial outcomes and clear FDA-approved indications: type 2 diabetes, chronic weight management, and since March 2024, cardiovascular risk reduction in adults with established heart disease who are overweight or obese.

They're often cited in healthspan discussions because large RCTs show benefits on major age‑related diseases including cardiovascular disease, kidney disease, obesity related heart failure and type 2 diabetes, Parkinson's disease progression, and dementia/cognitive impairment. However, there is no randomized evidence that GLP-1s extend lifespan or that they should be used as generalized “anti-aging” therapy in healthy people who don’t have obesity.

The bottom line

Peptides are biologically active compounds with legitimate medical applications for specific conditions, but the anti-aging marketplace has far outpaced both scientific evidence and regulatory oversight. Until rigorous human trials demonstrate clear healthspan benefits, these compounds remain experimental for longevity purposes.

If you're considering a peptide:

• Prioritize FDA-approved options for your specific condition only (vs “anti aging”) and work with a clinician who understands proper dosing, monitoring requirements, and the regulatory landscape.
• Quality and sterility are major concerns with gray-market products. The FDA has documented serious problems with some compounders and vendors, and self-injecting unapproved peptides carries significant risk.
• Be wary of “research-use-only” products sold online—these often violate FDA regulations and lack quality controls.
• Athletes should assume peptides are prohibited substances that could result in sanctions.

For now, the proven strategies for healthy aging—exercise, nutrition, sleep, stress management, and controlling blood pressure and glucose—remain your best investment while peptide science continues to develop.

— By Dr. David Dodick