A complete beginner's guide — from the chemistry basics to comparing suppliers
Last updated: April 2026 | Research use only — not medical advice
Research peptides are sold for laboratory and scientific research use only — not for human consumption. They are not FDA-approved drugs (with a few exceptions where the same molecule also exists as a pharmaceutical). This guide is educational. Nothing here constitutes medical advice. Consult a licensed physician before using any compound for health purposes.
A peptide is a short chain of amino acids linked together by peptide bonds. Amino acids are the molecular building blocks of all proteins — there are 20 standard ones, and the sequence and length of an amino acid chain determines what the molecule does.
Your body already makes thousands of different peptides that act as signals — hormones, neurotransmitters, growth factors, immune modulators. Insulin is a peptide. So is glucagon. So is the GLP-1 your gut releases after eating. Research peptides are typically synthetic versions of these naturally occurring signals, or engineered analogues designed to be more stable, more targeted, or longer-lasting than the natural version.
Peptides work by binding to specific receptor proteins on cell surfaces or inside cells. Think of it as a lock-and-key system: the peptide is the key, the receptor is the lock, and binding triggers a cellular response.
The critical concept is receptor specificity. A peptide designed to bind the GHS-R1a (ghrelin) receptor — like Hexarelin or Ipamorelin — won't bind a GLP-1 receptor and won't produce GLP-1 effects. Each peptide has a defined receptor target (or targets), which determines what it does.
It bypasses the digestive system, which would break down most peptides into individual amino acids before they could reach their target. Subcutaneous injection delivers the intact peptide into the bloodstream or local tissue.
Most peptides are small enough to circulate freely. Half-life varies enormously — from 7 minutes (Semax) to 6–8 days (CJC-1295 with DAC). Longer half-life = less frequent dosing needed.
The binding is highly specific. The peptide's shape matches the receptor's binding site — a complementary 3D fit. This triggers a conformational change in the receptor.
The receptor activation triggers an intracellular cascade — releasing second messengers, activating enzymes, or altering gene expression. This is where the biological effect happens.
Proteases (enzymes that break down proteins) degrade the peptide into its component amino acids. These are recycled by the body. Unlike small-molecule drugs, peptide metabolites are generally non-toxic amino acids.
The research peptide market covers several distinct biological categories. Understanding which category a peptide falls into tells you a lot about its mechanism and what it's studied for.
Target appetite, insulin, and metabolic regulation. Highest clinical evidence for weight loss.
Studied for wound healing, tendon/ligament repair, gut health, and angiogenesis (new blood vessel formation).
Activate ghrelin receptors to trigger growth hormone pulses from the pituitary. Used for GH restoration and body composition research.
Mimic growth hormone releasing hormone (GHRH) to prime pituitary GH production. Often stacked with GHRPs for synergistic GH release.
Target telomere biology, gene expression, and cellular aging mechanisms. Epithalon is the only peptide with evidence for telomerase activation.
Russian-developed peptides. Semax upregulates BDNF and NGF; Selank modulates GABA and anxiety response. Both approved drugs in Russia.
FDA-approved (as Vyleesi) for hypoactive sexual desire disorder. Acts centrally via melanocortin receptors — not through vascular mechanisms like sildenafil.
The legal landscape for research peptides is nuanced. Here's the practical breakdown for the US market:
| Status | What It Means | Examples |
|---|---|---|
| FDA-Approved Drug | Approved for specific human therapeutic use. Requires prescription. Also exists as research peptide (different market, different regulations). | Semaglutide (Ozempic/Wegovy), Tirzepatide (Mounjaro/Zepbound), PT-141 (Vyleesi) |
| Research Chemical (Legal) | Not FDA-approved for human use. Legal to purchase/possess for research. Cannot legally be sold for human consumption or with health claims. | BPC-157, TB-500, GHK-Cu, Epithalon, Hexarelin, Ipamorelin, Sermorelin, CJC-1295 |
| Approved Drug in Other Countries | Registered as a pharmaceutical elsewhere. Not FDA-approved. Sold as research chemical in the US. | Semax (Russia), Selank (Russia) |
| WADA Prohibited | Banned for competitive athletes in WADA-governed sports. Legal status and sports eligibility are separate issues. | Most GH peptides (Hexarelin, Ipamorelin, CJC-1295, Sermorelin, TB-500), Semaglutide, Tirzepatide |
The research peptide market varies significantly in quality. These are the factors that matter most when evaluating a supplier.
A COA from an independent lab confirms purity and identity. Look for HPLC (High-Performance Liquid Chromatography) purity testing — you want ≥98% purity. Mass spectrometry confirmation verifies the correct molecular structure. A supplier that won't provide a COA is a red flag. COAs should be dated and testable against the specific batch you're buying.
Always convert to $/mg. A 10mg vial at $100 is $10/mg. A 5mg vial at $55 is $11/mg — more expensive despite the lower sticker price. Our price comparison tool on the homepage does this automatically for every supplier we track.
Research peptides should be sold as lyophilized (freeze-dried) powder, not in solution. Peptides in solution degrade faster, especially without proper stabilizers. A well-lyophilized vial will have a uniform white cake or powder — not yellowing, not clumped. Avoid liquid-form peptides unless you have a specific reason.
Peptides degrade with heat, light, and moisture. Reputable suppliers ship in insulated packaging with ice packs in warmer months, store inventory refrigerated or frozen, and use light-blocking packaging. Lyophilized peptides are more tolerant of shipping conditions than reconstituted solutions, but proper cold-chain logistics still matter.
The research peptide community is active on forums (Reddit communities, specialized research forums). Suppliers develop reputations over time. Multiple years of consistent positive feedback about purity, shipping, and customer service is more meaningful than promotional claims on a supplier's own website.
US-accessible, competitive per-mg pricing on most peptides. Accepts crypto (typically 10% discount) and cards. COA available. Frequently best value for common peptides.
Consistent stock availability and reliable pricing. Frequently competitive on larger vial sizes. US domestic shipping. Well-regarded COA documentation.
US-based. Periodically runs bundle deals that are best value for stacking (e.g., CJC + Ipamorelin). Mid-range individual pricing.
US domestic. Strong reputation for PT-141 and BPC-157 pricing. Reliable shipping, good customer service track record.
Australian supplier. AUD pricing — competitive for Australian researchers, higher USD equivalent. Variable availability on some peptides.
US-based Shopify store. Broad peptide catalog. Pricing varies by peptide — check per-mg vs. other suppliers before ordering.
Most research peptides come as lyophilized powder and must be reconstituted with sterile liquid before use. Here's the standard process used in research settings.
The following describes standard laboratory reconstitution methodology for research purposes. It is not instructions for human use. Research peptides are not approved for human therapeutic use.
Bacteriostatic water (0.9% benzyl alcohol in sterile water) is the standard reconstitution medium for research peptides. It inhibits bacterial growth and extends the stable life of the reconstituted solution to 4–6 weeks refrigerated. Sterile water without benzyl alcohol can be used but results in a shorter stable window (24–48 hours).
A common approach is to add enough BW to create a round-number concentration. For a 5mg vial, adding 2.5mL of BW creates a 2mg/mL solution. Adding 5mL creates 1mg/mL. This makes dose calculation straightforward with standard insulin syringes.
Direct the BW stream along the inside wall of the vial, not directly onto the powder cake. This avoids mechanical disruption of the delicate lyophilized structure. Let the liquid settle and the powder dissolve — never shake the vial. Gentle swirling or rolling is appropriate if needed.
Keep away from light. Most reconstituted peptides are stable for 4–6 weeks under proper refrigeration. For longer-term storage, unconstituted lyophilized vials can be kept frozen for 12–24 months. Avoid repeated freeze-thaw cycles of reconstituted solutions.
| Peptide | Category | Primary Research Area | Typical Vial Size | Price Guide |
|---|---|---|---|---|
| Semaglutide | GLP-1 Agonist | Weight loss, diabetes, cardiovascular | 2–10mg | → Prices |
| Tirzepatide | GLP-1 + GIP Agonist | Weight loss, diabetes | 2–10mg | → Prices |
| Retatrutide | Triple Agonist | Weight loss (Phase 3) | 5–10mg | → Prices |
| BPC-157 | Tissue Repair | Healing, gut health, angiogenesis | 5mg | → Prices |
| TB-500 | Tissue Repair | Muscle/cardiac repair, cell migration | 2–10mg | → Prices |
| AOD-9604 | GH Fragment | Fat metabolism, joint health | 5–10mg | → Prices |
| Sermorelin | GHRH Analogue | GH restoration, body composition | 2–5mg | → Prices |
| CJC-1295 | GHRH Analogue | GH restoration (DAC = weekly dosing) | 2–10mg | → Prices |
| Ipamorelin | GHRP | GH pulse (cleanest, no cortisol) | 2–5mg | → Prices |
| Hexarelin | GHRP | GH pulse (most potent), cardiac | 2–5mg | → Prices |
| GHK-Cu | Longevity / ECM | Gene expression, collagen, skin aging | 50–100mg | → Prices |
| Epithalon | Longevity / Telomere | Telomerase activation, anti-aging | 5–10mg | → Prices |
| PT-141 | Melanocortin | Sexual desire (FDA-approved as Vyleesi) | 10mg | → Prices |
| Semax | Nootropic / ACTH Analogue | Cognitive function, BDNF, neuroprotection | 5–10mg | → Prices |
| Selank | Nootropic / Anxiolytic | Anxiety, BDNF, immune modulation | 5–10mg | → Prices |
Most peptides are broken down by digestive enzymes before they can reach the bloodstream intact. Subcutaneous injection bypasses the digestive system entirely, delivering the peptide directly into the tissue where it can be absorbed into circulation. A few peptides can be administered intranasally (Semax and Selank have nasal spray formulations in Russia) or orally for local gut effects (some BPC-157 research uses oral administration for gut-specific endpoints). But injectable delivery remains the standard for systemic research because it provides reliable, predictable bioavailability.
Key indicators of a legitimate research peptide supplier: (1) Third-party COAs from identifiable independent labs, dated and batch-specific; (2) HPLC purity ≥98%; (3) Years of operation with consistent community reviews; (4) Clear "for research use only" labeling — no human health claims; (5) Responsive customer service; (6) US-based or known international suppliers with established reputations. Red flags include: very low prices with no COA, health/therapeutic claims on the website, no verifiable business information, and new suppliers with no community track record.
Peptides and SARMs (Selective Androgen Receptor Modulators) are both sold in the research chemical market but are completely different classes of compounds. Peptides are chains of amino acids — naturally derived structures. SARMs are small synthetic molecules that bind androgen receptors to produce anabolic effects. SARMs are more controversial and face stricter regulatory scrutiny; the FDA has issued multiple warnings about SARMs. Peptides as a class have a different safety profile and different regulatory standing. The two are often sold by the same suppliers but should not be conflated.
Lyophilized (unconstituted) peptide vials can be stored at room temperature for short periods but are best kept refrigerated (2–8°C) or frozen (-20°C) for long-term storage of 6+ months. Once reconstituted with bacteriostatic water, solutions should be refrigerated at all times and used within 4–6 weeks. The key enemies of peptide stability are heat, moisture, light, and repeated freeze-thaw cycles. A refrigerator with a consistent temperature and light exclusion (keep vials in the box) is the standard storage approach.
No. Peptides and anabolic steroids are fundamentally different in structure, mechanism, and legal status. Anabolic steroids are synthetic derivatives of testosterone — small lipid-soluble molecules that bind androgen receptors and directly promote muscle protein synthesis. Peptides are chains of amino acids that work through specific receptor binding (most commonly hormone or growth factor receptors). GH peptides increase growth hormone, which has downstream anabolic effects, but this is physiologically different from direct androgen receptor activation. Most peptides are not scheduled controlled substances in the US; anabolic steroids are Schedule III controlled substances.