Peptides & the Biohacker's Toolkit: Complete Guide
Biohackers treat the human body like a system to be optimized. They track, test, tweak, and iterate. Peptides fit this mindset perfectly — they're precise biological tools that target specific pathways with measurable outcomes.
Biohackers treat the human body like a system to be optimized. They track, test, tweak, and iterate. Peptides fit this mindset perfectly — they're precise biological tools that target specific pathways with measurable outcomes. But the biohacking approach to peptides also carries real risks, especially when self-experimentation outpaces the science.
This guide maps the peptide landscape through a biohacker's lens: organized by goal, grounded in evidence, and honest about what we don't know.
Table of Contents
- The Biohacking Approach to Peptides
- Cognitive Enhancement Stack
- Recovery and Tissue Repair Stack
- Sleep Optimization Stack
- Anti-Aging and Longevity Stack
- Body Composition Stack
- Immune Optimization Stack
- Self-Quantification: Measuring What Matters
- Risks of Self-Experimentation
- When to Involve a Doctor
- Building Your Personal Protocol
- Frequently Asked Questions
- The Bottom Line
- References
The Biohacking Approach to Peptides
Biohacking is applied self-experimentation — using science, technology, and biology to optimize human performance. The movement grew from Silicon Valley engineer culture, where people accustomed to debugging code started applying the same systematic thinking to their bodies.
Peptides appeal to biohackers for several reasons:
Specificity. Unlike broad-spectrum supplements, peptides bind to specific receptors and trigger defined biological responses. CJC-1295 stimulates growth hormone release through GHRH receptors. Selank modulates anxiety through GABAergic and serotonergic pathways. This specificity allows targeted optimization.
Measurability. Most peptide effects can be tracked through blood work, body composition scans, sleep metrics, or cognitive testing. You can see IGF-1 levels rise on CJC-1295. You can measure sleep architecture changes with DSIP. You can track inflammatory markers responding to BPC-157.
Stackability. Peptides targeting different pathways can be combined. A biohacker might run a cognitive stack (Semax + Selank) alongside a recovery stack (BPC-157 + TB-500) and a body composition stack (CJC-1295 + Ipamorelin). Each targets different receptors with minimal overlap.
Programmability. Peptides can be cycled, stacked, dosed, and timed in ways that align with the biohacker's optimization mindset. Morning cognitive peptides, post-workout recovery peptides, evening sleep peptides — each serves a specific function in a daily protocol.
But this systematic approach has a shadow side. Biohackers often push ahead of the science, combining compounds that haven't been studied together, dosing based on Reddit threads rather than clinical data, and assuming that "more optimization" equals better outcomes. We'll address these risks directly.
For a broader overview of the biohacking and peptide movement, see our guide on peptides for biohackers.
Cognitive Enhancement Stack
Cognitive optimization is the crown jewel of biohacking. Clear thinking, fast recall, sustained focus, and creative problem-solving affect everything else in life. Several peptides show genuine cognitive effects, though the evidence varies.
Tier 1: Strongest Evidence
Semax — A synthetic ACTH(4-10) analog developed in Russia and approved there since 1996 for cognitive disorders and stroke recovery. Semax increases brain-derived neurotrophic factor (BDNF), which supports neuron survival, growth, and synaptic plasticity.
- Typical biohacker dose: 200-600 mcg intranasally, 1-2 times daily
- Onset: Effects often noticed within 30-60 minutes
- Primary benefits: Focus, mental clarity, working memory, motivation
- Side effects: Rarely reported; occasional headache, irritability at higher doses
- Evidence: Approved medication in Russia; limited Western clinical data
Selank — A synthetic analog of the immune peptide tuftsin, also approved in Russia. Acts on GABAergic and serotonergic systems. Provides anxiolytic effects similar to benzodiazepines without sedation, cognitive impairment, or dependence.
- Typical biohacker dose: 250-750 mcg intranasally, 1-3 times daily
- Onset: Anxiolytic effects within 30 minutes; cognitive effects build over days
- Primary benefits: Anxiety reduction, mood stabilization, focus under stress
- Side effects: Fatigue at higher doses in some users
- Evidence: Approved medication in Russia; preclinical and clinical Russian data
The Semax + Selank combination is the most popular cognitive peptide stack in the biohacking community. Semax provides stimulatory cognitive enhancement while Selank smooths out anxiety and stress responses. Together, they target both the "gas pedal" and "brake" of cognitive performance.
Tier 2: Promising but Less Proven
Dihexa — An angiotensin IV analog with extraordinary potency in preclinical models. Seven orders of magnitude more potent than BDNF at promoting synaptic connections. Crosses the blood-brain barrier orally.
- Typical biohacker dose: 10-40 mg orally
- Key concern: No human clinical trials. Extreme potency means unknown risk profile
- Best for: Biohackers comfortable with early-stage research compounds
PE-22-28 — A more recently identified nootropic peptide derived from the spadin family. Acts on TREK-1 channels, which are involved in depression and cognitive function.
- Evidence: Very early preclinical stage
- Risk level: High uncertainty; mechanism of action is still being characterized
Practical Cognitive Stack Protocol
A biohacker's cognitive protocol might look like this:
| Time | Peptide | Purpose |
|---|---|---|
| Morning (fasted) | Semax 400 mcg intranasal | Focus, motivation, BDNF |
| Morning | Selank 500 mcg intranasal | Anxiety buffering, mood |
| As needed (high-stress days) | Selank 250 mcg intranasal | Acute anxiety management |
Cycle: 4-6 weeks on, 2-4 weeks off. Some biohackers use Semax continuously with periodic breaks for Selank.
Check our best peptides for cognitive enhancement for more detail on each compound.
Recovery and Tissue Repair Stack
Every biohacker who trains hard — and most do — eventually deals with injuries, chronic soreness, or connective tissue problems. Peptides targeting tissue repair are among the most widely used in the biohacking community.
The BPC-157 + TB-500 Combination
BPC-157 and TB-500 are the two most popular healing peptides, often used together.
BPC-157 (Body Protection Compound-157) is a 15-amino acid peptide derived from human gastric juice. It promotes healing across virtually every tissue type studied: muscle, tendon, ligament, bone, gut, and brain. It works through multiple mechanisms including angiogenesis (new blood vessel formation), nitric oxide modulation, and growth factor upregulation.
TB-500 (Thymosin Beta-4 fragment) is a 43-amino acid peptide that promotes cell migration, blood vessel formation, and reduces inflammation. It has been studied extensively in cardiac repair and wound healing.
How they complement each other:
- BPC-157 has stronger anti-inflammatory and gut-healing properties
- TB-500 is better at promoting cell migration to injury sites
- BPC-157 appears to work more locally; TB-500 has more systemic effects
- Together, they address recovery from different angles
Typical biohacker recovery protocol:
| Peptide | Dose | Frequency | Duration |
|---|---|---|---|
| BPC-157 | 250-500 mcg | 1-2x daily, subcutaneous near injury site | 4-8 weeks |
| TB-500 | 2-5 mg | 2x per week, subcutaneous | Loading: 4-6 weeks; maintenance: 2x/month |
Evidence reality check: BPC-157 has hundreds of animal studies but no completed human clinical trials. TB-500 has some human wound-healing data but limited clinical trial evidence. Both are widely used in the biohacking and athletic communities based primarily on preclinical data and anecdotal reports.
Supporting Recovery Peptides
GHK-Cu — Copper peptide that promotes collagen synthesis, tissue remodeling, and reduces inflammation. Often used topically for skin injuries but also used subcutaneously by some biohackers for systemic recovery support.
CJC-1295/Ipamorelin — Growth hormone peptides that support recovery indirectly by increasing GH and IGF-1, both of which promote tissue repair, collagen synthesis, and protein synthesis. Many biohackers use these as a "base" for recovery protocols.
Sleep Optimization Stack
Sleep is the biohacker's force multiplier. Poor sleep undermines every other optimization. Several peptides directly affect sleep architecture and quality.
DSIP (Delta Sleep-Inducing Peptide)
DSIP is a neuropeptide that was discovered in 1977 during sleep research. It doesn't knock you out like a sedative — instead, it appears to promote delta wave sleep (deep, restorative sleep stages 3 and 4) while allowing normal sleep architecture.
- Typical biohacker dose: 100-300 mcg subcutaneous or intranasal, 30-60 minutes before bed
- Effects: Improved sleep onset, more time in deep sleep, more refreshing sleep
- Evidence: Mixed clinical results; some studies show significant improvement in insomnia patients, others show modest effects
CJC-1295/Ipamorelin for Sleep
Growth hormone is primarily released during deep sleep. CJC-1295 and Ipamorelin taken before bed may amplify this natural GH pulse, and many users report improved sleep quality as a primary benefit.
- Typical biohacker dose: CJC-1295 (no DAC) 100 mcg + Ipamorelin 100-200 mcg, subcutaneous, 30 minutes before bed on empty stomach
- Mechanism: GH release during sleep supports tissue repair, which may improve sleep depth
- Evidence: Clinical data on GH release; sleep improvement is an anecdotally reported effect, not a primary study endpoint
Selank for Sleep-Disrupting Anxiety
For biohackers whose sleep problems stem from anxiety or racing thoughts, Selank before bed can reduce the hyperarousal that prevents sleep onset. It won't make you drowsy — it reduces the mental noise that keeps you awake.
Practical sleep stack:
| Time | Peptide | Purpose |
|---|---|---|
| 30 min before bed | CJC-1295 100 mcg + Ipamorelin 200 mcg | GH optimization, deep sleep |
| 30 min before bed | DSIP 200 mcg (if using) | Delta wave promotion |
| As needed | Selank 500 mcg intranasal | Anxiety-related insomnia |
For a broader comparison, see best peptides for sleep quality.
Anti-Aging and Longevity Stack
Longevity optimization is the long game of biohacking. The peptides in this category target fundamental aging mechanisms rather than symptoms.
Epitalon — Targets telomere maintenance through telomerase activation. Used in short cycles (10-20 days) 2-3 times per year. Some biohackers combine it with telomere length testing to track effects over time.
MOTS-c — Mitochondrial-derived peptide that acts as an exercise mimetic. Improves metabolic function, insulin sensitivity, and mitochondrial efficiency. Levels decline with age and are elevated in centenarians.
Humanin — Another mitochondrial-derived peptide with broad cytoprotective effects. Protects against apoptosis, reduces oxidative stress, and shows neuroprotective properties.
GHK-Cu — Copper peptide that activates genes associated with a younger expression profile. Both topical (skin aging) and systemic (connective tissue, organ health) applications.
Typical longevity stack (advanced biohacker):
| Peptide | Protocol | Target |
|---|---|---|
| CJC-1295/Ipamorelin | 5 days on/2 off, ongoing with 1-month breaks quarterly | Hormonal optimization |
| Epitalon | 10 mg/day for 20 days, 2-3x per year | Telomere maintenance |
| GHK-Cu topical | Daily application | Skin aging, collagen |
| BPC-157 | 4-week cycles, 2-3x per year | Systemic anti-inflammatory |
See our complete guide on best peptides for anti-aging for deeper coverage.
Body Composition Stack
Improving the muscle-to-fat ratio is one of the most common biohacker goals. Peptides can support this through growth hormone optimization and metabolic regulation.
Growth Hormone Peptides
The CJC-1295/Ipamorelin combination remains the foundation of most body composition protocols. By increasing GH and IGF-1, these peptides support:
- Increased lean muscle mass
- Reduced body fat (particularly visceral fat)
- Improved recovery between training sessions
- Better sleep quality (which further supports body composition)
Tesamorelin is an FDA-approved GHRH analog that has clinical data showing significant reduction in visceral adipose tissue and liver fat. It's the most clinically validated peptide for body composition.
GLP-1 Agonists for Weight Management
Semaglutide and tirzepatide are FDA-approved peptide drugs that have transformed weight management. They reduce appetite, slow gastric emptying, and improve insulin sensitivity. Average weight loss in clinical trials ranges from 15-22% of body weight.
These aren't traditional biohacker peptides — they're prescription medications — but many biohackers incorporate them into body composition protocols. The key distinction: these are well-studied drugs with known safety profiles, unlike most research peptides.
MK-677 (Ibutamoren)
Technically not a peptide but a non-peptide GH secretagogue often discussed alongside peptide stacks. MK-677 is oral, which makes it convenient, but it increases hunger significantly and raises concerns about long-term IGF-1 elevation and insulin resistance.
Body composition protocol:
| Goal | Peptide Approach | Training Complement |
|---|---|---|
| Fat loss priority | CJC-1295/Ipamorelin + caloric deficit | Resistance training 3-4x/week + cardio |
| Muscle gain priority | CJC-1295/Ipamorelin + caloric surplus | Progressive overload resistance training |
| Recomposition | CJC-1295/Ipamorelin + maintenance calories | Hybrid resistance/cardio training |
| Significant weight loss | GLP-1 agonist (prescription) | Any consistent exercise program |
Our guide on best peptides for athletic performance covers training-specific protocols in more depth.
Immune Optimization Stack
Immune optimization becomes increasingly important with age (immunosenescence) and during high-stress periods. Two peptides stand out.
Thymosin Alpha-1 — Modulates immune function by promoting T-cell maturation and balancing Th1/Th2 responses. Approved in multiple countries for hepatitis and cancer adjunct therapy. Used by biohackers for general immune optimization, particularly during travel or cold/flu season.
- Typical biohacker dose: 1.6 mg subcutaneous, 2-3x per week
- Evidence: Strong clinical data for immune modulation
BPC-157 — Its broad anti-inflammatory and tissue-protective effects support immune function indirectly by reducing the inflammatory burden that impairs immune response.
LL-37 — An antimicrobial peptide that's part of the innate immune system. Some biohackers use it during acute infections, though clinical evidence for supplemental use is limited.
Self-Quantification: Measuring What Matters
The biohacker's mantra is "what gets measured gets managed." Peptide protocols are only as good as the data you collect to evaluate them.
Biomarkers to Track
Blood work (every 8-12 weeks on protocol):
- IGF-1 (should increase with GH peptides; target: upper third of normal range)
- Fasting insulin and glucose (monitor for insulin resistance)
- HbA1c (3-month glucose average)
- hs-CRP and IL-6 (inflammatory markers)
- Complete metabolic panel (liver, kidney function)
- Hormonal panel (GH, testosterone, estrogen, cortisol, thyroid)
Body composition (monthly):
- DEXA scan (gold standard for muscle mass, fat mass, bone density)
- Or bioimpedance scale (less accurate but more frequent tracking)
- Waist circumference (simple proxy for visceral fat)
Sleep metrics (continuous):
- Sleep stages via Oura Ring, WHOOP, or Apple Watch
- Total sleep time, sleep onset latency, deep sleep percentage
- Heart rate variability (HRV) during sleep
Cognitive assessments (monthly):
- Standardized tests: Cambridge Brain Sciences, BrainHQ, or Quantified Mind
- Reaction time testing
- Subjective journaling (energy, focus, mood on 1-10 scale)
Skin metrics (monthly for GHK-Cu users):
- Photography under consistent lighting
- Skin elasticity measurements (if available)
- Wrinkle depth assessments
Building a Tracking System
The best tracking system is one you'll actually use. Many biohackers use spreadsheets, but purpose-built apps work better for most people. Key principles:
- Establish baselines before starting any peptide (minimum 2 weeks of tracking)
- Change one variable at a time (the golden rule of self-experimentation)
- Track consistently — sporadic data is useless data
- Review data weekly and make adjustments based on trends, not daily fluctuations
- Document everything — doses, timing, injection sites, food intake, training, sleep
Risks of Self-Experimentation
Biohackers often underestimate risks because they overestimate their understanding. Here's what can go wrong.
Source Quality
The peptide supply chain for non-prescription compounds is largely unregulated. Research peptides sold online may contain:
- Incorrect amounts of active peptide (over- or under-dosed)
- Bacterial contamination
- Residual solvents from synthesis
- Wrong peptide entirely (mislabeled products)
Mitigation: Request certificates of analysis (COA) from suppliers showing HPLC purity (should be >98%) and mass spectrometry confirmation. Third-party testing from independent labs adds another layer of verification. See our guide on how to read a peptide COA.
Unknown Interactions
Most peptide stacks are based on theoretical compatibility, not clinical studies of the combination. Combining three or four peptides that individually appear safe doesn't guarantee the combination is safe. Potential issues include:
- Receptor competition (two peptides competing for the same receptor)
- Hormonal amplification (stacking GH peptides can push IGF-1 into supraphysiological ranges)
- Liver and kidney burden (processing multiple exogenous compounds simultaneously)
- Unknown synergistic toxicities
Sterility Risks
Reconstituting lyophilized peptides requires proper technique. Contamination during reconstitution or multi-use vial access can introduce bacteria. Injection site infections range from mild (localized redness) to severe (abscess requiring medical intervention).
Mitigation: Use bacteriostatic water (not sterile water), alcohol swabs for vial tops and injection sites, and proper subcutaneous injection technique. See our peptide injection guide and reconstitution guide.
Dosing Errors
Without standardized human dosing data for many research peptides, biohackers rely on animal study extrapolations, community reports, and practitioner recommendations. Dosing errors — particularly overdosing — can lead to unexpected side effects.
Regulatory Risk
The legal landscape for peptides is shifting. The FDA's 2024-2025 crackdown on compounded peptides restricted access to several popular compounds. Purchasing "research-use-only" peptides for personal use occupies a legal gray area that varies by jurisdiction.
When to Involve a Doctor
The biohacker ethos values self-reliance, but some situations require medical oversight.
You need a doctor when:
- Starting GH peptides (baseline and monitoring blood work is non-negotiable)
- Using GLP-1 agonists (prescription required, monitoring needed)
- You have existing health conditions (especially cancer history, diabetes, autoimmune conditions)
- You experience unexpected side effects
- You want to stack more than 2-3 peptides simultaneously
- Your blood work shows abnormal values
Finding a peptide-literate practitioner: Look for functional medicine doctors, anti-aging medicine specialists, or integrative medicine practitioners who are familiar with peptide therapy. Many offer telemedicine consultations. See our guide on choosing a peptide therapy clinic.
The middle ground: Many biohackers work with a practitioner for prescription peptides and monitoring while self-administering research-stage peptides. This provides medical oversight where it matters most (hormonal optimization, blood work interpretation) while preserving autonomy for lower-risk compounds.
Building Your Personal Protocol
Start Here: The Minimum Effective Stack
If you're new to peptide biohacking, start with the most evidence-supported compounds.
Beginner cognitive stack:
- Semax 400 mcg intranasal, morning (4-6 week trial)
Beginner recovery stack:
- BPC-157 250 mcg subcutaneous daily (for a specific injury or inflammation)
Beginner body composition stack:
- CJC-1295/Ipamorelin (require practitioner for proper dosing and monitoring)
Run each individually for 4-8 weeks. Measure baseline and endpoint. Only combine after you understand your individual response.
Intermediate Protocol (3-6 Months Experience)
After establishing individual responses, you can begin combining:
| Time | Stack | Purpose |
|---|---|---|
| Morning | Semax 400 mcg + Selank 500 mcg intranasal | Cognition + mood |
| Post-workout | BPC-157 500 mcg subcutaneous | Recovery |
| Before bed | CJC-1295 100 mcg + Ipamorelin 200 mcg subcutaneous | GH, sleep, body comp |
Advanced Protocol (12+ Months Experience)
Advanced protocols add anti-aging, immune, and targeted compounds. These should only be attempted with medical oversight and comprehensive monitoring. The peptide stacking guide and peptide cycling guide cover timing and cycling in detail.
Frequently Asked Questions
What's the most cost-effective peptide stack for a beginner? Semax intranasal is the lowest-cost entry point with measurable effects. A month's supply runs $30-60 from research peptide suppliers. BPC-157 for a 4-week cycle typically costs $50-100. These two address cognition and recovery without requiring blood work monitoring, making them the most accessible starting point.
How do biohackers get peptides? Three main routes: prescription through a peptide-literate physician (required for GLP-1 agonists, tesamorelin, and other FDA-approved peptides), compounding pharmacies (for peptides still available through compounding), and research peptide suppliers (for non-prescription compounds sold as "research use only"). Each carries different legal, quality, and safety considerations.
Can peptides replace nootropics like modafinil or racetams? Different tools, different mechanisms. Semax and Selank work through neurotrophic and neurotransmitter modulation, while modafinil promotes wakefulness through histamine and dopamine pathways. Some biohackers use both. Peptide nootropics tend to have subtler acute effects but better long-term neuroprotective profiles. Racetams work through different mechanisms (acetylcholine modulation) and can complement peptide nootropics.
Is it safe to use peptides every day long-term? Depends on the peptide. Topical GHK-Cu can be used daily indefinitely. GH peptides should be cycled (typical: 5 days on/2 off, with quarterly breaks). BPC-157 is usually run in 4-8 week cycles. Semax and Selank are cycled by most users (4-6 weeks on, 2-4 weeks off) though some Russian protocols recommend longer continuous use. The underlying principle: give your receptors periodic breaks to avoid desensitization.
What's the biggest mistake biohackers make with peptides? Stacking too many compounds too quickly. When you start five peptides simultaneously, you can't identify what's helping, what's causing side effects, or what's doing nothing. The most successful biohackers are methodical — they change one variable at a time, measure the response, and build systematically.
The Bottom Line
Peptides are the most precise tools in the biohacker's optimization toolkit. They target specific pathways, produce measurable results, and can be combined to address multiple goals simultaneously. But precision requires discipline.
Start with one compound. Establish baselines. Measure systematically. Add compounds one at a time. Work with a medical practitioner for anything involving hormonal manipulation. Source from reputable suppliers with third-party testing.
The biohacking approach works best when it stays scientific — when curiosity is tempered by caution, and n=1 experimentation is guided by the existing evidence rather than replacing it.
References
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- Pickart, L., et al. "GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration." BioMed Research International, 2015, 648108.
- Khavinson, V., et al. "AEDG peptide (epitalon) stimulates gene expression and protein synthesis during neurogenesis." Molecules, vol. 25, no. 3, 2020, 609.
- Wilkins, L.J., et al. "Delta sleep-inducing peptide: a review of physiology and pharmacology." Journal of Pineal Research, vol. 5, no. 1, 1988, pp. 53-68.
- McCormack, W.P., and Hoffman, J.R. "Caffeine, energy drinks, and strength-power performance." Strength and Conditioning Journal, vol. 34, no. 4, 2012, pp. 11-16.