Peptide Therapy: The Frontier of Functional Medicine

The Body’s Own Signaling Language

Your body speaks in peptides. Short chains of amino acids — two to fifty residues long — that function as signaling molecules, telling cells what to build, what to repair, when to inflame, and when to stand down. Insulin is a peptide. Oxytocin is a peptide. The thymus gland produces peptides that educate your entire immune system.

Therapeutic peptides are not drugs in the traditional sense. They are bio-identical messengers — copies of molecules the body already produces. Where a pharmaceutical drug often blocks a receptor or inhibits an enzyme (creating downstream side effects by shutting down natural physiology), a peptide amplifies a natural signal. It speaks the body’s own language, just louder.

This is why the side-effect profiles of most therapeutic peptides are remarkably clean compared to pharmaceutical agents. The body recognizes the molecule. It knows what to do with it.

Within the IFM framework, peptides address multiple matrix nodes simultaneously — immune modulation, tissue repair, gut healing, neuroendocrine signaling, detoxification support. They represent precision medicine at the molecular level.

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BPC-157: The Gut Guardian

Body Protection Compound-157 is a 15-amino-acid peptide originally isolated from human gastric juice. Your stomach makes this molecule to protect and repair its own lining — a tissue that faces hydrochloric acid, digestive enzymes, and mechanical stress with every meal. BPC-157 is why your stomach does not digest itself.

Mechanisms:

• Angiogenesis: Stimulates new blood vessel formation at injury sites via VEGF upregulation
• Tendon and ligament repair: Accelerates fibroblast migration and collagen deposition (Chang 2011 — tendon-to-bone healing in animal models)
• Gut mucosal healing: Repairs tight junctions, restores mucosal integrity, reverses NSAID-induced damage (demonstrated in multiple animal models where BPC-157 completely reversed indomethacin-induced GI lesions)
• Anti-inflammatory: Modulates NF-kB pathway
• Nitric oxide system: Balances the NO system — upregulates when deficient, downregulates when excessive
• Dopamine system normalization: Stabilizes dopaminergic signaling, counteracts damage from stimulants and opioids (Sikiric 1999)

Dosing Protocols:

• Subcutaneous injection: 250-500mcg, 1-2 times daily. Inject near the injury site for musculoskeletal conditions. Inject into abdominal subcutaneous tissue for gut healing.
• Oral capsules: 500mcg, 2 times daily on empty stomach. BPC-157 is one of the rare peptides stable in gastric acid — it evolved there. Oral route is effective specifically for gastrointestinal conditions.
• Cycle: 4-8 weeks on, then reassess. Some practitioners use longer courses for severe gut pathology.

Indications:

• Leaky gut (intestinal hyperpermeability) — the IFM 5R gut protocol’s best pharmaceutical ally
• Inflammatory bowel disease (Crohn’s, ulcerative colitis) — adjunctive
• NSAID-induced gastropathy and enteropathy
• Tendon and ligament injuries (Achilles, rotator cuff, tennis elbow, patellar)
• Muscle tears and strains
• Post-surgical healing acceleration
• Peripheral nerve damage and regeneration
• Traumatic brain injury (animal models show neuroprotection)
• Dopamine system recovery after stimulant or opioid use
• Gastroparesis

Safety: Hundreds of animal studies across two decades with no reported significant adverse effects at therapeutic doses. Human clinical trial data is emerging but limited. No known drug interactions. No known contraindications. This clean safety profile, combined with broad tissue repair capability, makes BPC-157 one of the most versatile peptides in functional medicine.

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Thymosin Alpha-1: The Immune Commander

The thymus gland — that small organ behind your sternum that shrinks after puberty — is the training ground for T-cells. Thymosin Alpha-1 (Ta1) is its primary product: a 28-amino-acid peptide that orchestrates adaptive immune function.

Mechanism:

• Enhances T-cell maturation and function (both CD4+ helper and CD8+ cytotoxic)
• Activates dendritic cells (the antigen-presenting sentinels)
• Increases natural killer (NK) cell activity
• Modulates Th1/Th2 balance toward Th1 (cell-mediated immunity — the branch that fights intracellular pathogens and cancer)
• Does not overstimulate — modulates. This is critical. It does not push autoimmunity; it corrects immune dysregulation.

Clinical Track Record: Thymosin Alpha-1 is FDA-approved in over 35 countries under the brand name Zadaxin for hepatitis B and C. It has been used clinically since the 1990s with extensive safety data. During COVID-19, multiple studies (Liu 2020, Yu 2020) demonstrated that Ta1 reduced ICU admission rates and mortality in critically ill patients by restoring lymphocyte counts and T-cell function.

Dosing:

• 1.6mg subcutaneous injection, daily or every other day
• Cycles: 2-3 months, then reassess
• Can be used continuously in chronic infection or cancer support settings

Indications:

• Chronic viral infections: EBV reactivation, hepatitis B/C, CMV, chronic COVID
• Lyme disease and co-infections (immune support alongside antimicrobials)
• Mold illness (mycotoxin exposure suppresses T-cell function)
• Cancer adjunctive: Enhanced immune surveillance, synergistic with checkpoint inhibitors
• Vaccine response enhancement (especially in elderly or immunocompromised)
• Primary or secondary immunodeficiency
• Autoimmune modulation (paradoxically, by restoring proper immune regulation)

Safety: One of the safest peptides in clinical use. Decades of human data. Mild injection site reactions are the most common side effect. No significant drug interactions. Can be used alongside chemotherapy, antimicrobials, and antivirals.

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TB-500 (Thymosin Beta-4): The Tissue Rebuilder

Where Ta1 commands the immune system, Thymosin Beta-4 (TB-500 is the synthetic version) commands tissue repair. This 43-amino-acid peptide is released by platelets at wound sites and orchestrates the healing cascade.

Mechanism:

• Promotes cell migration: Upregulates actin (the cytoskeletal protein that allows cells to move toward injury sites)
• Reduces inflammation throughout the repair process
• Angiogenesis: New blood vessel formation to supply healing tissue
• Reduces fibrosis and scar tissue formation (this is unique — most healing produces scar; TB-500 promotes more functional tissue)
• Hair follicle stem cell activation (hair regrowth)

Dosing:

• Loading phase: 2.5-5mg subcutaneous, 2 times per week for 4-6 weeks
• Maintenance: 2.5mg weekly for an additional 4-8 weeks
• Cycles: 8-12 weeks total, repeat as needed

Indications: Musculoskeletal injuries (tendon, ligament, muscle), wound healing (including surgical), cardiac repair (animal models show improved cardiac function post-MI), fibrosis reduction, hair loss, post-surgical recovery, chronic inflammation.

The BPC-157 + TB-500 Stack: These two peptides are synergistic and commonly stacked for injury recovery. BPC-157 handles the vascular and gut healing; TB-500 handles the structural repair and anti-fibrosis. Together, they cover the full spectrum of tissue restoration. Stack: BPC-157 250-500mcg + TB-500 2.5mg SubQ, both injected near the injury site or abdomen, for 4-8 weeks.

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KPV: The Anti-Inflammatory Tripeptide

KPV — just three amino acids (lysine-proline-valine) — derived from the C-terminal end of alpha-melanocyte stimulating hormone (alpha-MSH). Despite its tiny size, KPV is a potent anti-inflammatory that enters cells and shuts down the master inflammatory switch.

Mechanism:

• Enters cells and translocates to the nucleus
• Directly inhibits NF-kB activation — reducing production of TNF-alpha, IL-6, IL-1 beta
• Antimicrobial: Direct bactericidal activity (disrupts microbial membranes)
• Mast cell stabilization: Reduces histamine release and mast cell degranulation

Dosing:

• Oral capsule: 200-500mcg, 1-2 times daily (one of the few peptides effective orally for gut-targeted inflammation)
• Subcutaneous: 200-500mcg daily for systemic inflammation
• Topical: For skin conditions (emerging formulations)

Indications:

• Inflammatory bowel disease: Crohn’s disease, ulcerative colitis (oral route delivers directly to inflamed mucosa)
• SIBO-associated gut inflammation
• Mast cell activation syndrome (MCAS) — reduces the hyperactive mast cell response
• Skin inflammatory conditions (psoriasis, eczema) via topical or SubQ
• Systemic inflammation as adjunctive therapy

KPV’s oral effectiveness for gut inflammation makes it particularly valuable in functional medicine, where gut healing is central to the clinical model.

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CJC-1295 / Ipamorelin: The Growth Hormone Pulse

Growth hormone declines approximately 14% per decade after age 30. By age 60, most adults produce a fraction of the GH they made at 25. The consequences ripple through every system — loss of lean muscle, increased visceral fat, thinning skin, poor recovery, declining immune function, reduced bone density.

Exogenous growth hormone (HGH injections) works but suppresses the pituitary’s own production, creating dependency. The secretagogue approach is smarter: stimulate the pituitary to produce more of its own GH, preserving feedback loops and natural pulsatility.

CJC-1295 (with DAC): A growth hormone releasing hormone (GHRH) analog with a Drug Affinity Complex that extends its half-life to 6-8 days. It amplifies the natural GHRH signal, telling the pituitary: produce more GH.

Ipamorelin: A ghrelin receptor agonist — mimics the hunger hormone’s GH-releasing effect. Unlike older secretagogues (GHRP-6, GHRP-2), ipamorelin is clean: it does not spike cortisol or prolactin. Highly selective for GH release.

Combined Protocol:

• CJC-1295: 100mcg SubQ at bedtime
• Ipamorelin: 200-300mcg SubQ at bedtime (GH naturally peaks during deep sleep — timing amplifies this)
• Schedule: 5 days on, 2 days off (prevents receptor desensitization)
• Cycles: 3-6 months, then reassess
• Alternative: Some practitioners use ipamorelin alone at 200-300mcg, 2-3 times daily (pre-meal and bedtime)

Benefits: Increased lean muscle mass, visceral fat reduction, improved sleep quality and architecture (deeper slow-wave sleep), tissue repair and recovery, collagen synthesis (improved skin, joint health), enhanced immune function, improved bone mineral density. Does NOT suppress natural GH production.

Monitoring:

• IGF-1 levels: Target upper-normal range (200-280 ng/mL for most adults). Do not overshoot.
• Fasting glucose and insulin: GH can impair insulin sensitivity at supraphysiologic levels
• Joint symptoms: GH stimulates connective tissue growth — carpal tunnel or joint aches suggest dose reduction
• Lipid panel: GH improves lipid profile in most patients

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Selank and Semax: The Russian Nootropics

Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, these two heptapeptides represent decades of rigorous Soviet-era neuroscience applied to peptide therapeutics.

Selank (7 amino acids, derived from tuftsin — an immune peptide):

• Mechanism: Modulates GABA-ergic, serotonergic, and dopaminergic neurotransmission. Anxiolytic without sedation. Also enhances immune function through tuftsin pathway.
• Dosing: 200-400mcg intranasal, 1-3 times daily
• Indications: Generalized anxiety disorder, cognitive enhancement under stress, immune modulation. No addiction potential, no withdrawal symptoms, no tolerance development — unlike benzodiazepines.
• Safety: Approved for clinical use in Russia. Extensive human data. No significant adverse effects reported.

Semax (7 amino acids, derived from ACTH 4-10 fragment):

• Mechanism: Increases brain-derived neurotrophic factor (BDNF) — the molecule that builds and maintains neural circuits. Enhances attention, working memory, neuroprotection.
• Dosing: 200-600mcg intranasal, 1-2 times daily
• Indications: Cognitive decline, stroke recovery (approved in Russia for stroke), ADHD, TBI, optic nerve damage, depression
• Safety: Clinical use in Russia since 1990s. Well-tolerated. Occasional mild headache.

Both are administered intranasally — the nasal mucosa provides direct access to the brain via olfactory nerve pathways, bypassing the blood-brain barrier.

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PT-141 (Bremelanotide): Desire From the Brain

PT-141 is a melanocortin receptor agonist — specifically MC3R and MC4R in the hypothalamus. Unlike PDE5 inhibitors (sildenafil, tadalafil) that work on peripheral blood flow, PT-141 works centrally, in the brain, on the neural circuitry of desire itself. FDA-approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women (2019).

Dosing: 1.75mg SubQ, 45 minutes before sexual activity. Works in both men and women. Not daily — on-demand use.

Side effects: Nausea (common on first dose, usually resolves with subsequent use), flushing, headache. Temporary skin darkening possible (melanocortin effect). Limit to 8 doses per month.

Clinical role: For patients where sexual dysfunction is central to quality of life, and where hormonal optimization, neurotransmitter support, and relationship counseling have been addressed. PT-141 is not a first-line intervention — it is a targeted tool for persistent hypoactive desire after other factors are addressed.

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The Regulatory Landscape

Peptide therapy exists in a shifting regulatory environment. In 2023-2024, the FDA reclassified several peptides — including BPC-157 — to the “difficult to compound” category (Section 503B), making them unavailable through traditional compounding pharmacies in the United States. This does not mean they are dangerous; it means the regulatory framework has not kept pace with clinical use.

Practical guidance:

• Work with a knowledgeable prescribing physician (MD, DO, ND with prescriptive authority)
• Source from reputable compounding pharmacies that provide certificates of analysis (purity, sterility, endotoxin testing)
• Quality varies enormously between sources. Research-grade peptides sold online may contain contaminants, incorrect concentrations, or degraded product
• International access varies: many peptides available OTC in some countries, prescription-only in others
• Stay informed: Regulatory status changes frequently. The Alliance for Pharmacy Compounding and clinical peptide societies publish updates.

The peptide renaissance represents something profound in medicine — moving from blocking and suppressing natural systems to amplifying and restoring them. These molecules speak the body’s language. Our job is to learn when and how to use them.