UDP-glucuronosyltransferase (UGT) that catalyzes phase II biotransformation reactions in which lipophilic substrates are conjugated with glucuronic acid to increase the metabolite's water solubility, thereby facilitating excretion into either the urine or bile (PubMed:10359671, PubMed:18719240, PubMed:19022937, PubMed:19858781, PubMed:23288867, PubMed:23756265). Essential for the elimination and detoxification of drugs, xenobiotics and endogenous compounds (PubMed:10359671, PubMed:19858781, PubMed:23756265). Catalyzes the glucuronidation of endogenous steroid hormones such as androgens (testosterone and epitestosterone) and estrogens (estradiol and epiestriol) (PubMed:18719240, PubMed:19022937, PubMed:19858781, PubMed:23288867). Contributes to bile acid (BA) detoxification by catalyzing the glucuronidation of BA substrates, which are natural detergents for dietary lipids absorption (PubMed:23756265). Shows a high affinity to aliphatic odorants such as citronellol as well as olfactory tissue specificity, and therefore may be involved in olfaction (PubMed:10359671). Shows a potential role in detoxification of toxic waste compounds in the amniotic fluid before birth, and air- born chemical after birth (PubMed:19858781). {ECO:0000269|PubMed:10359671, ECO:0000269|PubMed:18719240, ECO:0000269|PubMed:19022937, ECO:0000269|PubMed:19858781, ECO:0000269|PubMed:23288867, ECO:0000269|PubMed:23756265}. This is the function of UGT2A1 (UDP glucuronosyltransferase family 2 member A1 complex locus, ENSG00000173610).