What Are the Most Common Types of Peptides Used in Therapy?

Peptide Therapy

If you are researching peptide therapy for the first time, one of the first things you will notice is that “peptides” is not a single treatment. It is a broad category that includes dozens of different compounds, each designed to interact with a specific biological pathway. Understanding the most common types of peptides used in therapy helps you have a more informed conversation with your provider and set realistic expectations for what treatment can accomplish.

1. What Makes Peptides Different From Each Other

Peptides are short chains of amino acids that act as signaling molecules in the body. What differentiates one peptide from another is the specific receptor it binds to and the biological response it triggers. Some peptides signal the pituitary gland to release growth hormone. Others accelerate tissue repair at the site of an injury. Still others regulate appetite, immune response, or sexual function.

This specificity is one of the key advantages of peptide therapy compared to broader hormonal interventions. Rather than flooding the system with a hormone across multiple pathways, a therapeutic peptide can target a precise mechanism with a relatively narrow set of downstream effects.

The peptides described below are among the most frequently used in clinical practice. This is not an exhaustive list, and the appropriateness of any specific peptide depends entirely on individual patient evaluation.

2. Growth Hormone Secretagogues

Growth hormone secretagogues are the most widely used category in peptide therapy. They work by stimulating the pituitary gland to produce and release more of its own growth hormone, rather than introducing synthetic growth hormone from outside the body.

Sermorelin is one of the most established peptides in this category. It is a synthetic analog of growth hormone-releasing hormone and signals the pituitary to release growth hormone in a pulsatile, physiologically natural pattern. It is frequently used for patients seeking improvements in body composition, recovery, energy, and sleep quality.

CJC-1295 is a longer-acting growth hormone-releasing hormone analog that maintains elevated growth hormone levels for a more extended period compared to sermorelin. It is often combined with ipamorelin for a synergistic effect.

Ipamorelin is a growth hormone-releasing peptide that stimulates growth hormone release through a different receptor pathway than CJC-1295. The CJC-1295 and ipamorelin combination is one of the most commonly prescribed protocols in clinical peptide therapy because the two compounds amplify each other’s effect while keeping the release pattern relatively natural.

Tesamorelin is an FDA-approved growth hormone-releasing hormone analog originally developed for HIV-associated lipodystrophy. It has demonstrated significant effects on visceral fat reduction and is used in some metabolic and body composition protocols.

According to a review published by the National Institutes of Health, growth hormone secretagogues demonstrate meaningful effects on body composition, sleep architecture, and metabolic markers in both younger and older adults, supporting their use in a broad range of clinical contexts.

3. Tissue Repair and Recovery Peptides

This category includes peptides that accelerate healing at the cellular level, reduce inflammation, and support recovery from both injury and exercise.

BPC-157 (Body Protection Compound 157) is one of the most researched peptides in this category. It was originally derived from a protein found in gastric juice and has shown significant regenerative properties in soft tissue, tendon, ligament, muscle, and gut lining repair. Athletes and physically active patients use it to accelerate recovery from training and injury.

TB-500 (Thymosin Beta-4) is a naturally occurring peptide that promotes cell migration and proliferation, supports angiogenesis (new blood vessel formation), and reduces inflammation. It is commonly used alongside BPC-157 in recovery-focused protocols because the two work through complementary pathways.

Research highlighted by the National Library of Medicine on thymosin beta-4 confirms its role in tissue repair and wound healing, supporting its clinical use in recovery protocols for both acute injuries and chronic conditions.

4. Metabolic and Weight Management Peptides

Several peptides directly influence metabolism, fat storage, and appetite regulation. These are often incorporated into medical weight loss protocols alongside or in place of GLP-1 medications, depending on the patient’s specific metabolic profile.

AOD-9604 is a modified fragment of human growth hormone specifically designed to target fat metabolism without affecting insulin levels or growth. It has been studied for its ability to reduce abdominal fat and support weight management in patients who are not candidates for growth hormone therapy.

5-Amino-1MQ is a smaller molecule compound that inhibits an enzyme called NNMT, which regulates fat cell metabolism. By inhibiting NNMT, this compound increases the metabolic activity of fat cells, making them more likely to burn stored energy. It is used in metabolic health protocols aimed at improving body composition.

MOTS-c is a mitochondrial-derived peptide that regulates metabolic homeostasis and has shown benefits in improving insulin sensitivity and exercise capacity. It is increasingly used in protocols targeting metabolic syndrome and age-related metabolic decline.

5. Immune and Anti-Inflammatory Peptides

Some of the most clinically significant peptides work through immune modulation, reducing chronic inflammation and supporting immune system balance.

Thymosin Alpha-1 is a naturally occurring peptide produced by the thymus gland that plays a central role in regulating immune function. It is used clinically in several countries for immune support in patients with chronic infections, autoimmune conditions, and post-illness recovery. It is one of the few peptides with extensive human clinical trial data.

LL-37 is an antimicrobial peptide produced naturally by the body that also plays a role in immune signaling. It is being studied for its applications in addressing chronic infections and inflammatory skin conditions.

6. Sexual Health Peptides

A smaller but clinically important category of peptides targets sexual function and libido directly through the central nervous system.

PT-141 (Bremelanotide) is a melanocortin receptor agonist that works centrally through the brain rather than through the vascular system. Unlike PDE5 inhibitors that work by increasing blood flow, PT-141 activates dopamine pathways associated with sexual arousal. It is FDA-approved for hypoactive sexual desire disorder in premenopausal women and is used off-label in men for libido support and erectile dysfunction. It is often considered alongside testosterone replacement therapy or bioidentical hormone replacement therapy for patients whose sexual health concerns have a hormonal component.

7. How Peptides Are Selected for a Protocol

The selection of peptides for a specific patient is never arbitrary. A qualified provider evaluates several factors before recommending any compound.

Your goals drive the initial selection. A patient focused on body composition and recovery will be evaluated differently from one seeking immune support or improved sleep. Your lab results, including growth hormone, IGF-1, and relevant hormone panels, provide objective data to guide decisions. Your health history identifies any conditions that might affect peptide selection or contraindicate specific compounds.

Most effective protocols use combinations of peptides that work through complementary pathways rather than a single compound in isolation. The combination of CJC-1295 with ipamorelin is one example. BPC-157 combined with TB-500 for recovery is another.

Dosing, delivery method, and treatment duration are also individualized. Most therapeutic peptides are administered via subcutaneous injection for consistent bioavailability, though some are available in oral or nasal forms depending on the compound and indication.

8. Frequently Asked Questions

How do I know which type of peptide is right for me?

The right peptide protocol is determined by your specific health goals, current hormone and metabolic lab results, and your health history. There is no universal protocol. A thorough evaluation by a qualified provider who specializes in peptide therapy is the starting point for any treatment decision.

Can multiple peptides be used at the same time?

Yes, and combination protocols are common in clinical practice. Peptides that work through different receptor pathways can be combined for complementary effects without producing interference. The CJC-1295 and ipamorelin combination and the BPC-157 and TB-500 pairing are two of the most frequently used combinations.

Are all peptides injected?

No, though subcutaneous injection is the most common delivery method for peptides that require systemic action because it provides the most consistent bioavailability. Some peptides are available in oral, nasal, or topical forms, though these formats are generally considered less effective for compounds that need to reach the bloodstream intact.

How long does peptide therapy last?

Protocol duration varies significantly depending on the peptide and the treatment goal. Growth hormone secretagogue protocols typically run three to six months in cycles. Tissue repair protocols may run six to twelve weeks depending on the severity of the injury or condition being addressed. Your provider establishes the appropriate timeline based on your goals and response to treatment.

Are there peptides that help with both weight loss and recovery?

Yes. Some growth hormone secretagogues, particularly in combination protocols, support both goals simultaneously by improving growth hormone output, which promotes fat metabolism while also accelerating tissue repair and recovery. BPC-157 is also being studied for its effects on gut health and metabolic function beyond its established role in tissue repair.

Is peptide therapy appropriate for women as well as men?

Yes. Peptide therapy is used in both men and women, though the specific peptides and dosing may differ. Women undergoing hormonal transitions during perimenopause or post-menopause often incorporate peptide therapy alongside BHRT to address aspects of health optimization that hormone therapy alone does not fully cover.

Understanding the types of peptides used in therapy gives you a meaningful foundation for evaluating whether peptide therapy fits your health goals. The right protocol depends entirely on your individual biology, and no general overview can substitute for a proper clinical evaluation.

Key Takeaways

The most common types of peptides used in therapy fall into five broad categories: growth hormone secretagogues, tissue repair peptides, metabolic peptides, immune-modulating peptides, and sexual health peptides. Each category targets a different biological system, which is why peptide protocols are always personalized to the patient’s specific goals and lab results. No single peptide addresses everything, and the most effective protocols typically combine compounds that complement each other. A qualified provider evaluates your health history, hormone levels, and treatment goals before recommending any specific peptide or combination.

Curious Which Peptides Match Your Goals? Schedule a Consultation to Find Out.

If you are curious about which peptides are appropriate for your specific goals, speaking with a provider who specializes in peptide therapy is the most direct and productive next step available to you. A personalized evaluation will tell you what your lab results show, which compounds are relevant to your situation, and what a realistic treatment plan looks like for you specifically.

Disclaimer: This content is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before beginning any treatment.

References:

National Institutes of Health. Growth hormone secretagogues and sleep architecture. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6461327/
National Library of Medicine. Thymosin beta-4 and tissue repair. https://pubmed.ncbi.nlm.nih.gov/20526669/