Conn. Agencies Regs. § 12-426-13
The gross receipts from the sale, and the storage, use or other consumption in this state of medicine by prescription only shall be exempt from the Sales and Use Tax.
"Medicine by prescription" means drugs and medicines commonly known and regarded as such by druggists or pharmacists, including biologics, antibiotics, hormones, and similar medicinal items prescribed for the specific treatment of disease by persons authorized by the laws of this state to issue prescriptions. Syringes and needles by prescription are also exempt.
This exemption provided for medicine by prescription shall also include those drugs and medicines falling within the above classifications such as insulin, adrenal cortex, etc., which are of such a character that the need for same and the proper amount to be administered cannot be determined without an initial diagnosis and a prescribed dosage by a person duly authorized to issue prescriptions in this state and accordingly they may be purchased tax free even though the purchaser may not be in possession of the original prescription.
Vitamins are exempt only when purchased on prescription.
All refillable prescriptions are tax exempt on subsequent purchases.
Such drugs or medicines are also exempt from tax when purchased by a physician, dentist or veterinarian for use by him in his profession.
Conn. Agencies Regs. § 12-426-13