# peptide

/ˈpɛpˌtaɪd/ (US) · /pˈɛptaɪd/ (UK)

Source: https://englishreference.com/word/peptide
Updated: 2026-08-27

## Senses

### 1. chemical compound

noun · CEFR C1 · Technical

a small molecule made of amino acids that are linked together.

For teachers: a compound consisting of two or more amino acids linked in a chain, the carboxyl group of each acid being joined to the amino group of the next by a bond.

- The scientist studied how the peptide chain folds into a specific shape.
- Short-chain peptides act as signaling molecules in the body, regulating various physiological processes including hormone release and immune response.

### 2. performance-enhancing drug

noun · CEFR C2 · Informal · Slang

a type of supplement or drug used by athletes to build muscle or recover faster.

For teachers: a euphemistic reference to synthetic performance-enhancing drugs, often marketed for muscle growth or anti-aging properties.

- He was banned from the competition after testing positive for banned peptides.
- The rise of underground labs selling unapproved peptides has created significant challenges for anti-doping agencies worldwide.

## Examples

- The scientist studied how the peptide affects skin cells.
- Many modern skincare products include synthetic peptides to help the skin produce more collagen naturally.
- Research into antimicrobial peptides suggests they may provide a new way to fight bacteria that have become resistant to traditional antibiotics.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.