The best replacement for peptide is protein.

The best alternatives to peptide are rated as following:
★★★★★  protein
★★★★  polypeptide
★★★  steroid hormones
★★  amino acid
★  steroid
★  peptoid
★  l-glutamine
★  amide
★  small molecule
★  amine
  brain natriuretic peptide
  steroid hormone
  hormone
  b-type natriuretic peptide
  bnp

Your alternative for peptide is not listed? Suggest!
Speaking about peptide, one probably shouldn't forget about siloxane.

Other search terms related to peptide and their ratings are:
★★★★★ siloxane
You have in mind a companion for peptide and it is not yet here? Propose!



Google Trends

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peptide
protein
polypeptide