Peptide Therapy — What It Is and Who It's For

Peptide therapy has moved from the fringes of anti-aging medicine into broader medical conversations. Athletes talk about them. Longevity clinics promote them. Social media is full of claims about their benefits. And if you've done any research, you've probably encountered a confusing landscape of abbreviations — BPC-157, CJC-1295, Ipamorelin, PT-141 — with varying levels of evidence behind each one.

Here's a physician's take on what peptide therapy actually is, what the evidence supports, and where healthy skepticism is warranted.

What Are Peptides?

Peptides are short chains of amino acids — typically between 2 and 50 amino acids linked together. They're essentially small proteins. Your body produces hundreds of peptides naturally, and they serve as signaling molecules — telling cells what to do. Hormones like insulin, growth hormone-releasing hormone (GHRH), and oxytocin are all peptides.

Therapeutic peptides are synthetic versions of these natural signaling molecules, designed to mimic or enhance specific biological functions. They're administered via subcutaneous injection, nasal spray, oral capsule, or topical application, depending on the peptide.

The appeal of peptide therapy is its specificity. Rather than broad systemic effects (like taking a hormone), peptides can target specific pathways — healing, growth hormone release, sexual function, immune modulation, or tissue repair — with theoretically fewer off-target effects.

The Regulatory Landscape

This is important context. Most therapeutic peptides used in clinical practice are not FDA-approved drugs. They fall into a few categories:

• FDA-approved peptides: Some peptides have gone through full FDA approval — semaglutide (a GLP-1 peptide for weight loss/diabetes), tesamorelin (for HIV-associated lipodystrophy), and bremelanotide/PT-141 (for hypoactive sexual desire disorder in women) are examples.
• Research peptides: Many peptides used clinically are available through compounding pharmacies under physicians' clinical judgment. They haven't gone through FDA approval for their commonly prescribed uses.
• Recently restricted peptides: In 2023-2024, the FDA moved to restrict certain popular peptides (including BPC-157) from compounding pharmacies, citing lack of sufficient safety data. This landscape is evolving.

This means the evidence base for many peptides comes from animal studies, small human studies, and clinical observation rather than the large randomized controlled trials required for FDA approval. That doesn't necessarily mean they don't work — it means the level of certainty is lower than for FDA-approved medications.

Commonly Used Peptides

Growth Hormone Secretagogues

These peptides stimulate your pituitary gland to release more of your own growth hormone (GH), rather than injecting synthetic GH directly.

CJC-1295 / Ipamorelin: Often used in combination. CJC-1295 is a growth hormone-releasing hormone (GHRH) analog that extends the GH release pulse. Ipamorelin is a growth hormone secretagogue that stimulates GH release without significantly affecting cortisol or prolactin.

What they're used for: Improved sleep quality, body composition (reduced fat, preserved lean mass), recovery from exercise, skin quality, and general anti-aging.

The evidence: Growth hormone has well-documented effects on body composition, sleep, and tissue repair. The question with secretagogues is whether the magnitude of GH increase they produce is clinically meaningful. Small studies and clinical experience suggest benefits, but large-scale trials are limited.

Who might benefit: Adults over 35-40 with declining GH levels, poor sleep quality, slow recovery from exercise, or interest in body composition optimization. Not appropriate for anyone with active cancer (GH can promote growth of existing tumors).

Healing and Recovery Peptides

BPC-157 (Body Protection Compound-157): Derived from a protein found in gastric juice, BPC-157 has demonstrated impressive healing properties in animal studies — accelerating healing of tendons, ligaments, muscles, nerves, and gut lining. It's been one of the most popular therapeutic peptides.

The reality check: Almost all BPC-157 research is in animal models. Human clinical trial data is extremely limited. The animal data is compelling, but extrapolating animal results to humans is always uncertain. Additionally, the FDA's recent restrictions on BPC-157 compounding have reduced access.

TB-500 (Thymosin Beta-4): Another healing peptide with animal data supporting tissue repair, wound healing, and anti-inflammatory effects. Similar limitations apply — strong preclinical data, limited human trials.

Sexual Health Peptides

PT-141 (Bremelanotide): This peptide acts on melanocortin receptors in the brain to increase sexual desire. Unlike PDE5 inhibitors (Viagra, Cialis) that work on blood flow mechanics, PT-141 works on the neurological component of arousal.

FDA-approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women. Used off-label in men as well.

The evidence: Clinical trials demonstrated meaningful improvement in sexual desire and distress scores. It works differently from erectile dysfunction medications and can be effective when those medications are insufficient — particularly when the issue is desire rather than mechanics.

Immune and Anti-Inflammatory Peptides

Thymosin Alpha-1: Used to modulate immune function. Has some evidence for supporting immune response in immunocompromised patients and has been used in various countries for hepatitis B and C treatment.

KPV (Lysine-Proline-Valine): A tripeptide with anti-inflammatory properties, used primarily for gut inflammation and skin conditions. Early-stage research.

Who Is Peptide Therapy For?

Peptide therapy may be appropriate for:

• Adults experiencing age-related decline in recovery, sleep, body composition, or vitality
• Patients with soft tissue injuries looking for adjunctive healing support
• Men and women with sexual health concerns that haven't responded to first-line treatments
• Patients interested in proactive health optimization under physician supervision

Peptide therapy is NOT appropriate for:

• Anyone with active cancer or a history of cancer (particularly for GH secretagogues)
• Patients seeking a magic bullet — peptides work best as part of a comprehensive health strategy
• Anyone unwilling to commit to monitoring and follow-up
• People purchasing peptides from unregulated online sources without physician oversight

The Importance of Physician Oversight

This cannot be overstated. Peptides purchased online from research chemical companies or gray-market suppliers come with zero guarantees of purity, potency, or sterility. Contaminated or mislabeled products are a real risk.

Legitimate peptide therapy involves:

• A thorough medical evaluation before prescribing
• Baseline lab work (including IGF-1 for GH secretagogues, metabolic panel, CBC)
• Sourcing from licensed compounding pharmacies that follow USP 797/800 standards
• Regular follow-up and lab monitoring
• Honest discussion of evidence levels — what's proven, what's promising, and what's speculative

At CORAL, Dr. Tae Y. Kim, DO, takes a lab-based, evidence-informed approach to peptide therapy. That means we won't oversell what the data doesn't support, and we won't prescribe without proper evaluation and monitoring.

Frequently Asked Questions

Are peptides the same as steroids?

No. Peptides are signaling molecules that tell your body to do something it already does — like release growth hormone or accelerate healing. Steroids are synthetic hormones that directly replace or supplement your body's hormone levels. The mechanisms, risks, and regulatory classifications are different.

How are peptides administered?

Most therapeutic peptides are given as subcutaneous injections (similar to insulin injections). Some are available as nasal sprays, oral capsules, or topical creams. Your physician will determine the appropriate route based on the specific peptide and your treatment goals.

How long does peptide therapy take to work?

This varies by peptide and indication. Growth hormone secretagogues typically show noticeable effects on sleep within 1-2 weeks, with body composition changes over 2-3 months. Healing peptides may show benefits within weeks. Sexual health peptides (PT-141) can work within hours of administration.

Is peptide therapy covered by insurance?

Most peptide therapy is not covered by insurance, as many peptides are used off-label and sourced from compounding pharmacies. FDA-approved peptides (like bremelanotide) may have some coverage depending on your plan.

Are peptides safe?

When prescribed by a knowledgeable physician, sourced from reputable compounding pharmacies, and monitored appropriately, peptide therapy has a favorable safety profile. The risks increase substantially when peptides are obtained from unregulated sources or used without medical supervision.

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Curious about whether peptide therapy might be right for your goals? CORAL offers evidence-based consultations to evaluate your health profile and determine which — if any — peptides are appropriate. [Start your consultation](/start).