Specifications under 21 CFR Part 111: identity, purity, strength, and composition

At the core of US supplement cGMP is a deceptively simple idea: decide in advance what your ingredients and products must be, then prove they are. Those decisions are 'specifications,' and 21 CFR Part 111 requires them for identity, purity, strength, and composition. They are the yardstick every batch is measured against.

What a specification is

A specification is a defined requirement a material must meet — the identity of an ingredient, its purity, its strength (potency), and the composition of the finished product, plus limits on contaminants. Part 111 requires manufacturers to establish these specifications in writing before production, not to discover them afterward.

Identity testing of incoming ingredients

Part 111 specifically requires identity testing of incoming dietary ingredients — confirming an ingredient actually is what the supplier says. This is a non-negotiable inspection point: relying on a supplier's label alone, without verifying identity, is a classic cGMP failure. The manufacturer owns the verification.

Finished-product specifications

Beyond ingredients, the finished product needs specifications for strength, composition, and limits on contaminants, and the manufacturer must confirm they're met before release. This is where label claim, overage, and testing all connect: the product must actually contain what the panel declares, within the specified limits.

Why specs anchor the whole system

Specifications are the reference point for testing, for the MMR, for quality control disposition, and for justifying overages. Vague or missing specs unravel everything downstream. Setting clear, defensible specifications — and keeping them tied to each formula — is the foundation the rest of cGMP is built on.

This is general information, not regulatory or legal advice. US requirements change and turn on specifics, so confirm the current rules with the FDA, FTC, or a qualified US regulatory expert before relying on them.

Where Lemoniq fits

Lemoniq holds each product as one structured formula — ingredients, amounts, specifications, sourcing, and the documentation behind them — and generates what US dietary supplement manufacturing needs from that single source: the Supplement Facts panel, the claim and disclaimer wording, the records that cGMP expects, and the data to back overages, dating, and origin. Compliance becomes a property of the formula, not a pile of separate documents.

The takeaway

The US supplement model trades pre-market approval for full manufacturer responsibility, which means the work shifts onto documentation, accurate labeling, and defensible formulas. The brands that scale in the US are the ones whose single source-of-truth formula generates each label, specification, and record correctly — every time, across every product.

Lemoniq turns one formula into compliant, US-ready outputs — panel, claims, specs, and documentation — from a single source. We solve this exact problem. See how it works