Frequently asked
What are peptides?
Peptides are molecules made from two or more amino-acid residues joined by peptide bonds. In everyday biomedical use, the term usually refers to amino-acid chains smaller than proteins, although the exact size boundary is not absolute. Their biological activity depends on sequence, structure and chemical modifications rather than on the word “peptide” alone. — sources: IUPAC Gold Book — peptides, NCBI MeSH — Peptides, NCBI/NCI — peptide definition
How do peptides work in the body?
Many endogenous peptides act as signalling molecules. They bind to receptors, enzymes, membranes or other molecular partners and change cellular behaviour such as hormone release, metabolism, inflammation, growth or tissue signalling. Different peptides can have completely different targets, so “peptides” should never be treated as one biological effect. — sources: Nature Reviews Drug Discovery — Trends in peptide drug discovery, AAMC — 10 questions to ask your doctor about peptides, Tufts Medicine — Peptides explained
What is the difference between peptides and proteins?
Both peptides and proteins are built from amino acids. Peptides are generally shorter chains, while proteins are usually longer and more likely to adopt complex three-dimensional structures. The boundary is conventional rather than absolute, so sequence length alone does not fully determine whether a molecule is called a peptide or protein. — sources: NCBI MeSH — Peptides, Nature Reviews Drug Discovery — Trends in peptide drug discovery
Are peptides steroids?
No. Peptides are amino-acid chains linked by peptide bonds, whereas steroids are molecules built around a characteristic four-ring carbon framework. Some peptides and some steroids can influence overlapping physiological systems, which is why they are sometimes discussed together, but chemically they are very different classes of molecule. — sources: IUPAC Gold Book — peptides, Harvard Health — Peptides: benefits and safety concerns
Are peptides hormones?
Some peptides are hormones, but many are not. Insulin, glucagon, oxytocin and many other signalling molecules are peptide hormones, while other peptides function as neurotransmitters, growth factors, antimicrobial molecules, research probes or synthetic drug candidates. “Peptide” describes chemistry; “hormone” describes biological function. — sources: Nature Reviews Drug Discovery — Trends in peptide drug discovery, AAMC — 10 questions to ask your doctor about peptides
Are peptides the same as amino acids?
No. Amino acids are the individual molecular building blocks. Peptides are formed when two or more amino-acid residues are joined, typically through peptide bonds. A peptide’s properties emerge from the sequence, length, charge, conformation and modifications of its component residues. — sources: IUPAC Gold Book — peptides, NCBI MeSH — Peptides
What is a peptide bond?
A peptide bond is the amide linkage that connects the carbonyl carbon of one amino-acid residue to the nitrogen of another. Repeating peptide bonds create the backbone of peptide chains. The sequence and side chains attached to that backbone determine much of a peptide’s chemistry and biological recognition. — sources: IUPAC Gold Book — peptides
How many amino acids are in a peptide?
There is no universally rigid cutoff. Peptides contain at least two amino-acid residues; terms such as oligopeptide, polypeptide and protein overlap, and different fields use somewhat different length conventions. It is better to state the actual sequence length than rely on a single arbitrary peptide/protein boundary. — sources: NCBI MeSH — Peptides, IUPAC Gold Book — peptides
Are peptides natural or synthetic?
Both. Living organisms produce many peptides naturally, while laboratories can synthesize identical sequences, analogues or entirely designed sequences. Synthetic chemistry also allows non-natural amino acids, cyclization, lipidation and other modifications that can alter stability, potency or pharmacokinetics. — sources: Nature Reviews Drug Discovery — Trends in peptide drug discovery, PubMed — Fmoc Solid-Phase Peptide Synthesis
Why can two peptides have completely different effects?
A change in amino-acid sequence can alter charge, shape, receptor affinity, stability and cellular distribution. Even closely related peptides can therefore engage different targets or behave differently in solution and in vivo. Sequence and structure, not the generic label “peptide,” determine function. — sources: Nature Reviews Drug Discovery — Trends in peptide drug discovery, PubMed — Factors affecting peptide aggregation
Terminology
The NBetaX ladder: NBetaX (platform and therapeutic class) → N-BX (translational candidate family) → N-BX01 (lead candidate). The canonical name decomposes as Nuclear βeta-catenin eXclusion.
The target protein is indexed as beta-catenin, β-catenin, beta catenin, CTNNB1 (its gene) and catenin beta-1.
The pathway is indexed under Wnt: Wnt signalling (UK) / Wnt signaling (US), the canonical Wnt pathway, and the Wnt/β-catenin pathway, with its nuclear effectors TCF/LEF and TCF4, the co-activator BCL9, and the destruction-complex proteins Axin, APC and GSK3β. The nuclear step is described as nuclear translocation, nuclear localisation or nucleocytoplasmic distribution. PubMed indexes 69 records for endometriosis AND "Wnt signaling" (count verified 2026-09-08) — the literature of this programme lives under the Wnt vocabulary even though the programme's own name does not contain it.
The disease terms: endometriosis, endometriotic lesion, ectopic endometrium, eutopic endometrium, endometrioma and deep infiltrating endometriosis. Adenomyosis is an adjacent condition, not the same one.
The category terms: non-hormonal endometriosis treatment, disease-modifying endometriosis therapy, precision peptide, lesion regression, protein-protein interaction inhibitor, peptidomimetic, cell-penetrating peptide and stapled peptide.
