Welcome to the Ultimate List of Peptides, the Bio Peptide Calculator peptide library: a plain-English reference to the 95 peptides people research most, plus the free tools to dose them accurately.

Collagen Peptides

Collagen peptides are different from most of the compounds on this page. They are short chains of amino acids made by breaking down collagen protein (usually from bovine, marine, or porcine sources) into small, easily absorbed pieces — also called hydrolyzed collagen. Unlike the injectable research peptides above, collagen peptides are an oral dietary supplement, taken as a powder or capsule, and are generally recognized as safe.

People use collagen peptides mainly for skin elasticity and hydration, joint comfort, and hair and nail strength, with a growing body of research supporting skin and joint benefits. Collagen is the most abundant protein in the body, and natural production declines with age, which is the rationale behind supplementing. Because they are a food-derived supplement rather than a research chemical, collagen peptides do not require reconstitution or dosing calculators — they are simply mixed into food or drink.

Peptides by Use

A quick way to navigate the field is by what each peptide is researched for. Below are the most common categories. Many peptides appear in more than one category, and none of this is medical advice — it is a map of how these compounds are typically discussed in research.

Peptides for Weight Loss

This is the fastest-moving category, driven by the GLP-1 class and newer multi-receptor agonists. The most researched include Semaglutide (Ozempic, Wegovy), Tirzepatide (Mounjaro, Zepbound), the investigational Retatrutide, Liraglutide, CagriSema, Cagrilintide, Survodutide, Mezdutide, and the oral Orforglipron. Fragment and metabolic compounds like AOD9604, hGH Fragment 176-191, MOTS-c, SLU-PP-332, and BAM-15 are also studied for fat loss. Use the dosage calculators for the GLP-1 compounds to convert mg to units.

Peptides for Muscle Growth

These compounds are researched for muscle building, strength, and body composition, largely by influencing growth hormone, IGF-1, or myostatin. Key examples include IGF-1 LR3 (see our IGF-1 LR3 muscle growth guide), Follistatin-315 and Follistatin-344, MGF and PEG-MGF, MK-677, and the growth-hormone-releasing peptides Ipamorelin, CJC-1295 DAC, ModGRF 1-29, GHRP-2, GHRP-6, and Hexarelin.

HGH & Growth Hormone Peptides

Rather than being growth hormone itself, these peptides stimulate the body’s own production or mimic parts of it. This group includes Sermorelin, Tesamorelin, CJC-1295 DAC, ModGRF 1-29, Ipamorelin, GHRP-2, GHRP-6, Hexarelin, GHRH, and the oral secretagogue MK-677. They are frequently combined in research (for example a GHRH analogue paired with a GHRP).

Healing & Recovery Peptides

Studied for tissue repair, injury recovery, and inflammation, this group is led by BPC-157 and TB-500, often researched together. Others include KPV and LL-37 for inflammation and immune defense, GHK-Cu for regeneration, and blends like Klow.

Skin, Hair & Cosmetic Peptides

These are researched or used for appearance — skin, collagen, tanning, and wrinkles. The best known is GHK-Cu (copper peptide) for collagen and anti-aging, alongside GHK Basic, the cosmetic peptide Snap8, Melanotan 2 for tanning, Glutathione for skin brightness, and the branded Lemon Bottle for fat dissolving.

Nootropic & Cognitive Peptides

Researched for focus, memory, mood, and neuroprotection, this group includes Semax and Selank (and their N-Acetyl amidate forms), Cerebrolysin, P21, FGL, PE-22-28, DNSP-11, plus the non-peptide nootropics Noopept, 9-Me-BC, and Methylene Blue.

Longevity & Anti-Aging Peptides

This category focuses on cellular aging, mitochondria, and telomeres. It includes Epithalon and its N-Acetyl form, NAD+, MOTS-c, Humanin, SS-31, FOXO4-DRI, and the large family of Khavinson bioregulator peptides (such as Cardiogen, Pinealon, Vilon, and others).

Sexual Health & Hormone Peptides

Studied for libido, reproductive hormones, and related pathways, this group includes PT-141 (Bremelanotide) for sexual desire, Kisspeptin-10, Gonadorelin, Oxytocin, Triptorelin, and Melanotan 2.

Gut & Immune Peptides

Researched for digestive health and immune modulation, this group includes BPC-157 and KPV for the gut, Larazotide for intestinal barrier research, Thymosin Alpha 1 and VIP for immune function, and GLP2 for intestinal growth.

What Are Peptides?

Peptides are short chains of amino acids, the same building blocks that make up proteins. The difference is size: peptides are small, typically 2 to 50 amino acids, while proteins are much larger chains. That small size lets peptides act as precise signaling molecules — they bind to receptors and tell cells what to do, whether that is releasing a hormone, repairing tissue, or reducing appetite.

Your body already makes thousands of peptides naturally. Insulin is a peptide. So is oxytocin. The peptides discussed in the research community are usually synthetic versions of natural signaling molecules, or engineered analogues designed to last longer or target a specific receptor more strongly. This is why a single peptide can have such a specific, targeted effect compared with a broad supplement.

What Do Peptides Do?

Because each peptide is shaped to fit a particular receptor, what a peptide does depends entirely on which one it is. There is no single “peptide effect.” Instead, different peptides are researched for very different purposes, which is why the categories above exist.

Broadly, the peptides people research fall into a few functional buckets: metabolic peptides that influence blood sugar, appetite, and fat (the GLP-1 class and its relatives); growth-hormone-related peptides that signal the pituitary or mimic growth factors; regenerative peptides studied for healing and recovery; cosmetic peptides for skin and collagen; cognitive peptides for focus and neuroprotection; and longevity peptides aimed at cellular aging. A peptide’s mechanism — the receptor it targets — is what determines its category and its effects.

Are Peptides Safe?

Safety depends heavily on which peptide, its source, its purity, and how it is used. Some peptides are FDA-approved medications with well-characterized safety profiles — semaglutide, tirzepatide, liraglutide, and tesamorelin are prescribed drugs. Many others are sold strictly as “research chemicals,” which means they have not been approved for human use and their long-term safety in people is not established.

Two issues drive most of the real-world risk. The first is product quality: research-chemical peptides are not regulated as drugs, so purity, dosing accuracy, and contamination vary widely between sources. The second is dosing: because these are potent signaling molecules, small errors in reconstitution or measurement matter, which is exactly why accurate dosage calculation is important. The safest path is always to work with a qualified healthcare professional, use approved products where they exist, and treat anything sold “for research use only” with appropriate caution. Nothing on this page is medical advice.

Peptides for Sale: Where Do People Buy Peptides?

This is one of the most searched questions in the space, and it deserves an honest answer rather than a marketing one. We have no affiliation with any peptide vendor, we accept no payment or affiliate commissions for placement, and we do not sell peptides ourselves. Because of that independence, we are not going to hand you a ranked “best vendor” list — and here is the important part: no one can honestly give you a reliable, current popularity ranking, because the research-peptide market has no official directory, vendor quality shifts over time, and most “top 10” lists you will find are published by the vendors themselves or by affiliate sites earning a commission on every click.

What actually exists is a rolling, informal consensus among researchers — most visibly on Reddit’s r/Peptides community — based on user-reported lab testing and transparency. A vendor widely praised two years ago may have changed suppliers or testing practices since, and at least one long-standing “top” vendor (Peptide Sciences) has closed entirely. So instead of a leaderboard that would be out of date within months, here is what genuinely lets you find where reputable buyers go, and evaluate any store yourself.

How to tell a legitimate vendor from a risky one

Independent sources consistently converge on the same checkable criteria. A vendor worth considering will have all of these; a vendor missing any of them is a warning sign:

• Batch-specific third-party COAs. A real Certificate of Analysis comes from a named, independent lab, carries a lot number that matches the label, and shows both a purity percentage and a molecular-weight confirmation (HPLC and mass spectrometry). In-house-only testing means little.
• Lyophilized (freeze-dried) powder, not pre-mixed solutions, which preserves stability during shipping and storage.
• A verifiable business. A real physical address, responsive support, and a substantial track record — not an anonymous, email-only storefront that appeared last month.
• Realistic pricing. Quality peptide synthesis is expensive. Prices far below the market (for example a BPC-157 vial at a third of everyone else’s price) usually signal purity or dosing problems.
• Products labeled “for research use only,” not “for human consumption.” Vendors marketing research chemicals for human use are ignoring the law and are a red flag, not a convenience.

Where the real consensus lives

If you want to see where people actually report buying and what their testing showed, go to the primary community source rather than any single site’s ranking. Reddit’s r/Peptides is the most active hub, where buyers post COAs, third-party retests, and contamination reports; the discussion there is the closest thing to a live, crowd-sourced verdict. Cross-reference any vendor you are considering against recent threads, and look for independent retests rather than the vendor’s own marketing. This approach — verify the COA, check the community, apply the checklist above — will serve you far better than trusting any static list, including one we could have written.

Note: laws on buying, possessing, and using research peptides vary by country and region, and many are not approved for human use. This section explains how people evaluate vendors; it is not an endorsement to purchase or use any research chemical. Always follow your local laws and consult a healthcare professional.

Frequently Asked Questions About Peptides

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Disclaimer: This page is for general education only and is not medical advice. Many peptides described here are sold strictly as research chemicals and are not approved for human use. Always consult a qualified healthcare professional and follow the laws in your area before considering any peptide.