Based on the building components, hormones are classified into four types:
Amino acid derivatives - Thyroid, Norepinephrine and Epinephrine are derived from the amino acid tyrosine.
Peptides- Oxytocin, Vasopressin and Parathyroid hormone
Proteins - Trophic hormones, insulin, glucagon, relaxin
Steroids - Oestrogen, testosterone, estradiol, progesterone