Hormones generally fall into 3 categories: lipid-based, amino acid-based, and peptide-based. Lipid-based hormones are mostly derived from cholesterol, so they have a similar structure. Amino acid hormones are usually derived from the amino acids tyrosine and trytophan. Peptide hormones are made of small-chain polypeptides, or small or large proteins. They include oxytocin and antidiuretic hormone (ADH) on the polypeptide side, small proteins like growth hormones, large glycoproteins like follicle-stimulating hormone (FSH), and proteins produced in the vesicles of cells like insulin.
- Steroid hormones are derived from cholesterol: testosterone, estrogens, progesterone, DHEA and cortisol (the stress hormone from the adrenal glands).
- Amino acid derived hormones: melatonin, thyroid hormones and many neurotransmitters in nerve cells and the brain.
