API reference · v1 (1.0.0)

Peptide Library API reference

Generated from the OpenAPI 3.1 document that describes the live API (also as YAML).

Overview

Base URL: https://api.peptidelibrary.app/v1. Every response is JSON over HTTPS. The version is in the path; v1 only gains fields and endpoints, never loses or renames them. Breaking changes would ship as v2 with notice in the changelog.

{
  "data": [ … ],
  "pagination": { "next_cursor": "eyJvIjoyMH0…", "has_more": true, "total": 182, "limit": 20 },
  "meta": { "api_version": "v1", "request_id": "req_…", "retrieved_at": "2026-10-18T14:00:00.000Z", … }
}

Authentication

Research and study endpoints work without a key, limited per IP address. Vendor, product and price endpoints need a key with the matching scope. Create keys in the developer dashboard; a key is shown once and stored only as a hash.

Authorization: Bearer pl_live_…
# or
X-API-Key: pl_live_…

research:read: Peptide profiles, research summaries, regulatory status, categories, search. Also works without a key.
studies:read: Cited studies and the studies index. Also works without a key.
vendors:read: Vendor directory, profiles, shipping and comparisons.
products:read: Products (compound × form) with price ranges.
pricing:read: Current offers with listed prices and affiliate links.

Keep keys on your server. Never put a key in a web page, a mobile app or a public repository; rotate it if it leaks.

Pagination, filters and fields

List endpoints take limit (1-100) and return pagination.next_cursor; pass it as cursor with the same filters for the next page. A cursor made for other filters is refused. Unknown parameters are refused too, so a typo never silently returns everything. Most lists take fields (comma-separated top-level fields).

Rate limits and caching

Keyed vendor, product and price requests count against your plan per account (Free Developer: 60 per minute, 5,000 per month, reset on the 1st, UTC). Responses carry RateLimit-Limit, RateLimit-Remaining, RateLimit-Reset and X-RateLimit-Monthly-*. Over a limit you get 429 with Retry-After. Anonymous requests are limited to about 300 a minute per IP address. Nothing is billed automatically.

Responses carry an ETag; send it back as If-None-Match to get 304 Not Modified. Research data changes rarely (cached up to an hour); prices are refreshed about once a day and cached for at most 10 minutes.

Data conventions

Timestamps are UTC ISO 8601. Money is a decimal string ("29.99") in the listed currency; never converted.
Research fields a profile doesn't document are the string not_documented; unknown vendor and price fields are null. Nothing is guessed or filled in.
Human (clinical) evidence and preclinical (animal, lab, in vitro) evidence are always kept apart.
No dose figures, regimens, reconstitution or injection instructions are ever returned.
Prices: last_seen_at says when a price was last seen on the vendor's site; is_stale after 7 days; offers unseen for 30 days are dropped. Prices for different strengths, package sizes, forms or currencies are never treated as the same product.
Shipping status unknown is never shown as ships.

Errors

{ "error": { "code": "insufficient_scope", "message": "…", "request_id": "req_…", "details": { "required_scope": "pricing:read" } } }

invalid_parameter	400	A parameter is missing, unknown or out of range. `details.parameter` names it.
invalid_cursor	400	The cursor is malformed or was made for different filters.
missing_key	401	The endpoint needs a key and none was sent.
invalid_key	401	The key is malformed or unknown.
revoked_key	401	The key was revoked or rotated.
insufficient_scope	403	The key lacks the endpoint's scope (`details.required_scope`).
account_suspended	403	The developer account is suspended.
not_found	404	No such endpoint or resource. Peptide lookups include `details.suggestions`.
method_not_allowed	405	The API is read-only: only GET, HEAD and OPTIONS.
response_too_large	422	Lower `limit` or narrow the filters.
rate_limited	429	Over your per-minute limit (or the per-IP limit). Wait `Retry-After` seconds.
quota_exceeded	429	Your plan's monthly limit is used up until `details.reset_at`.
internal_error	500	Our fault. Quote `request_id` if you contact us.
backend_unavailable	503	A data source is briefly unavailable. Retry with backoff.
auth_unavailable	503	Keys can't be checked right now. Retry shortly.

Attribution and use

Show “Data from Peptide Library” with a link to the page each result returns (url), keep vendor links as returned, show prices with their last_seen_at, and present the data as research and education, not medical advice. Peptide Library may earn a commission when you buy through these links, at no cost to you. Commissions never affect which offers are listed or their order. Prices are as last seen on the vendor's site; check the vendor before relying on them.

Full terms: API terms of use. Research and educational information only. Not medical advice, and not a recommendation to buy or use any substance. Many of these compounds are not approved for human use.

Research

Peptide research profiles, research summaries, regulatory status, categories and search. No key needed.

GET/v1/peptides

List and search peptides

Peptide research profiles with filters. `search` matches names, synonyms and aliases (fuzzy). Each result links to its canonical Peptide Library page.

Scope research:read · key optional · paginated

Query parameter	Type	Description
search	string	Name, synonym, alias or partial name.
category	"fat-loss" \| "cognitive" \| "muscle-recovery" \| "longevity" \| "glp1-metabolic" \| "cosmetic" \| "experimental"	Research category id (see /v1/categories).
research_area	string	Studied research area, e.g. "tissue repair" (see /v1/research-areas).
evidence_level	"fda-approved" \| "established-human" \| "clinical-trial" \| "limited-human" \| "preclinical" \| "insufficient"	Evidence level of reviewed profiles.
regulatory_status	"approved" \| "investigational" \| "experimental" \| "withdrawn" \| "insufficient"	Regulatory class from the recorded FDA status.
sort	"relevance" \| "name" \| "-name" \| "evidence" \| "updated"	Order: `relevance` (default with `search`), `name` (default), `-name`, `evidence`, `updated`.
limit	integer	Results per page (1-100, default 20).
cursor	string	Opaque cursor from `pagination.next_cursor` of the previous page.
fields	string	Comma-separated fields to return for each item (`id` is always included). One of: id, name, also_known_as, categories, summary, research_topics, classification, fda_status, evidence, url, regulatory_status, content_reviewed_at, api_url.

curl "https://api.peptidelibrary.app/v1/peptides?search=bpc&limit=5"

Response fields: PeptideSummary

id	string
name	string
also_known_as	string[]
categories	object[]
summary	string \| "not_documented"
research_topics	string[]
classification	string \| "not_documented"
fda_status	string \| "not_documented"
evidence	object
url	string
regulatory_status	"approved" \| "investigational" \| "experimental" \| "withdrawn" \| "insufficient"	Regulatory class read from the profile's FDA status.
content_reviewed_at	string \| "not_documented"
api_url	string	Absolute URL.

peptide	object
evidence	object
mechanisms	object
clinical_evidence	object
preclinical_evidence	object
secondary_reports	object
regulatory_evidence	Study[]
safety	object
limitations	string[]
research_gaps	string[]	Evidence steps with no documented source in the profile.
references	object[]
review	object

id	string
label	string
description	string
peptide_count	integer
url	string	Absolute URL.
peptides	object[]

Query parameter	Type	Description
search	string	Part of an area name.
limit	integer	Results per page (1-100, default 20).
cursor	string	Opaque cursor from `pagination.next_cursor` of the previous page.

Query parameter	Type	Description
qrequired	string	What to search for.
types	string	Comma-separated: `peptides`, `content` (default both).
limit	integer	Results per page (1-25, default 10).

query	string
peptides	PeptideSummary[]
peptide_total	integer
content	ContentResult[]
content_total	integer
unavailable_sources	string[]

id	string \| null	Stable id from the study's identifier (`pmid-…`, `doi-…`, `nct-…`); null when it has none.
title	string
publication_year	number \| "not_documented"
authors	"not_documented"	Not stored by Peptide Library.
journal	"not_documented"	Not stored by Peptide Library.
doi	string \| null
pmid	string \| null
nct_id	string \| null
study_type	string \| "not_documented"
research_model	"human" \| "animal_or_lab" \| "in_vitro" \| "regulatory_label" \| "secondary_report"
population	string \| "not_documented"
sample_size	number \| "not_documented"
summary	string \| "not_documented"	The finding as summarised by Peptide Library editors (dose figures removed).
evidence_classification	"regulatory_label" \| "human_controlled_trial" \| "human_study" \| "secondary_report" \| "animal_or_lab" \| "in_vitro"
evidence_classification_label	string
analog_compound	boolean	Research on a related compound, not this one.
limitations	string[]
source_url	string \| "not_documented"

Query parameter	Type	Description
peptide	string	Only studies cited by this peptide (id, name or alias).
evidence_classification	string	Comma-separated classifications.
year_from	integer	Earliest publication year.
year_to	integer	Latest publication year.
search	string	Words in the title.
sort	"newest" \| "oldest" \| "title"	`newest` (default), `oldest` or `title`.
limit	integer	Results per page (1-100, default 20).
cursor	string	Opaque cursor from `pagination.next_cursor` of the previous page.
fields	string	Comma-separated fields to return for each item (`id` is always included). One of: id, title, publication_year, authors, journal, doi, pmid, nct_id, study_type, research_model, evidence_classification, evidence_classification_label, source_url, cited_by.

Query parameter	Type	Description
search	string	Vendor name or alias.
country	string	Where the vendor is based (ISO 3166-1 alpha-2).
ships_to	string	Only vendors that ship to this destination (country "US" or subdivision "US-CA"). Unknown coverage is left out.
product_category	"peptides" \| "sprays" \| "capsules" \| "other"	Only vendors with live listings of this product type.
min_rating	number	Minimum average rating (0-5).
peptide	string	Only vendors with live listings of this peptide (id, name or alias).
sort	"best_match" \| "rating" \| "reviews" \| "popular" \| "products" \| "name" \| "-name"	Order (default `best_match`).
limit	integer	Results per page (1-100, default 20).
cursor	string	Opaque cursor from `pagination.next_cursor` of the previous page.
fields	string	Comma-separated fields to return for each item (`id` is always included). One of: id, slug, name, description, logo_url, country, region, website_url, profile_url, product_categories, rating, catalog, shipping, api_url.

id	string	Stable vendor id.
slug	string
name	string
description	string \| null
logo_url	string \| null
country	string \| null
region	string \| null
website_url	string	Peptide Library link to the vendor's site (may be an affiliate link).
profile_url	string	Absolute URL.
product_categories	"peptides" \| "sprays" \| "capsules" \| "other"[]
rating	object
catalog	object
shipping	object
api_url	string	Absolute URL.

Query parameter	Type	Description
idsrequired	string	2-4 comma-separated vendor ids or slugs.
ships_to	string	Shipping destination: ISO 3166-1 alpha-2 country ("US") or subdivision ("US-CA"). Adds `ships_to` to each result; `unknown` is never treated as ships.

vendors	Vendor[]
rows	object[]
note	string

id	string	Compound and form, e.g. `bpc-157::vial`.
peptide	object
form	"vial" \| "solution" \| "pen" \| "nasal_spray" \| "oral_spray" \| "spray" \| "capsule" \| "tablet" \| "topical" \| "liquid" \| "bulk_powder" \| "other" \| "unknown"
product_type	"peptides" \| "sprays" \| "capsules" \| "other"
offer_count	integer
vendor_count	integer
in_stock_count	integer
prices	object[]	Per currency, never converted or mixed.
last_seen_at	string \| null
api_url	string	Absolute URL.

id	string	Compound and form, e.g. `bpc-157::vial`.
peptide	object
form	"vial" \| "solution" \| "pen" \| "nasal_spray" \| "oral_spray" \| "spray" \| "capsule" \| "tablet" \| "topical" \| "liquid" \| "bulk_powder" \| "other" \| "unknown"
product_type	"peptides" \| "sprays" \| "capsules" \| "other"
offer_count	integer
vendor_count	integer
in_stock_count	integer
prices	object[]	Per currency, never converted or mixed.
last_seen_at	string \| null
api_url	string	Absolute URL.

vendor	object
ships_to	object \| null	Shipping to the `ships_to` destination you asked about; null when you didn't ask. `unknown` is never shown as ships.
coverage	"verified" \| "partial" \| "unknown"
destinations	string[]	Countries, US-XX states or groups (EU, EEA, WORLDWIDE) the vendor lists.
excluded	string[]
ships_internationally	boolean \| null
ships_from	string \| null
processing_time	string \| null
methods	object[]
free_shipping	object \| null
returns	object \| null
policy_url	string \| null
last_verified_at	string \| null
sources	object

Query parameter	Type	Description
search	string	Product or compound name.
peptide	string	Peptide id, name or alias.
category	string	Comma-separated product types.
form	string	Comma-separated forms: vial, solution, pen, nasal_spray, oral_spray, spray, capsule, tablet, topical, liquid, bulk_powder, other, unknown.
ships_to	string	Shipping destination: ISO 3166-1 alpha-2 country ("US") or subdivision ("US-CA"). Adds `ships_to` to each result; `unknown` is never treated as ships.
in_stock	boolean	Only in-stock offers.
sort	"name" \| "offers" \| "vendors"	Order (default `name`).
limit	integer	Results per page (1-100, default 20).
cursor	string	Opaque cursor from `pagination.next_cursor` of the previous page.
fields	string	Comma-separated fields to return for each item (`id` is always included). One of: id, peptide, form, product_type, offer_count, vendor_count, in_stock_count, prices, last_seen_at, api_url.

id	string	Offer id.
product_id	string
product_name	string	As the vendor lists it.
peptide	object
vendor	object
product_type	"peptides" \| "sprays" \| "capsules" \| "other"
form	"vial" \| "solution" \| "pen" \| "nasal_spray" \| "oral_spray" \| "spray" \| "capsule" \| "tablet" \| "topical" \| "liquid" \| "bulk_powder" \| "other" \| "unknown"
strength	object
price	string	Decimal amount as a string, never a float.
regular_price	string \| null
currency	string
price_per_mg	string \| null
price_per_unit	string \| null
availability	"in_stock" \| "out_of_stock"
ships_to	object \| null	Shipping to the `ships_to` destination you asked about; null when you didn't ask. `unknown` is never shown as ships.
last_seen_at	string \| null	When the price was last seen on the vendor's site.
is_stale	boolean	True when not seen in the last 7 days.
first_seen_at	string \| null
price_changed_at	string \| null
product_page_url	string	Peptide Library redirect to the vendor's page; logs the click.
is_affiliate_link	boolean

Query parameter	Type	Description
peptiderequired	string	Peptide id, name or alias.
form	string	Comma-separated forms.
currency	string	ISO 4217 currency.
ships_to	string	Shipping destination: ISO 3166-1 alpha-2 country ("US") or subdivision ("US-CA"). Adds `ships_to` to each result; `unknown` is never treated as ships.
in_stock	boolean	Only in-stock offers.

name	string
version	string
release	string
documentation	string	Absolute URL.
openapi	string	Absolute URL.
endpoints	object[]

status	"ok" \| "degraded"
database	"ok" \| "unavailable"
release	string

Peptide Library API reference

Overview

Authentication

Pagination, filters and fields

Rate limits and caching

Data conventions

Errors

Attribution and use

Research

GET/v1/peptides

GET/v1/peptides/{slug}

GET/v1/peptides/{slug}/research

GET/v1/regulatory-status/{slug}

GET/v1/categories

GET/v1/research-areas

GET/v1/search

Studies

GET/v1/peptides/{slug}/studies

GET/v1/studies

GET/v1/studies/{id}

Vendors

GET/v1/vendors

GET/v1/vendors/compare

GET/v1/vendors/{id}

GET/v1/vendors/{id}/shipping

GET/v1/vendors/{id}/products

GET/v1/vendors/{id}/prices

Products

GET/v1/products

GET/v1/products/{id}

Prices

GET/v1/prices

GET/v1/prices/compare

Meta

GET/v1

GET/v1/health