4-Hydroxyretinoic acid (4-HRA) is a naturally occurring retinoid derivative with diverse biological effects. 4-Hydroxyretinoic acid is formed from retinol catalyzed by cytochrome P-450 isozyme(s), and is mainly metabolized by the liver in the body. 4-Hydroxyretinoic acid also serves as the substrate for human liver microsomal UDP-glucuronosyltransferase(s) and recombinant UGT2B7. 4-Hydroxyretinoic acid regulates gene expression and cell differentiation via binding to nuclear receptor RAR (Retinoic Acid Receptor), and activates RARs and RXR-alpha, to induce cancer cell apoptosis. In addition, 4-Hydroxyretinoic acid is also involved in various physiological processes such as immune regulation, neuroprotection, and anti-oxidation.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.