What compounding means
Making medicine to order is known as compounding.
It can be done by a pharmacist or doctor, or by a business that makes medicines and is registered with FDA, the U.S. drug agency.
Pharmacies and doctors can work under a law called section 503A. Medicine-making businesses can register with FDA under section 503B.
Registration puts the business on an FDA list. Being on that list gives no FDA approval to the business or its medicines.
FDA says a made-to-order medicine can fill a need that an approved drug leaves unmet. It may also help when the approved drug is not available to buy.
What FDA has not checked
At the September 2026 check, compounded drugs still had no FDA approval.
FDA does not check how well these medicines work, how safe they are or their quality before they go on sale.
That is true even when a pharmacy follows sound practices.
Poor preparation may put germs in a drug or leave it with more or less active ingredient than intended.
A medicine’s active ingredient is the substance intended to do its work.
Why a reason for your case matters
For pharmacies and doctors working under section 503A, the September 2026 rules limit copies of medicines already sold.
They cannot make those copies as a regular practice or in large amounts.
An exception can apply if the person writing your prescription finds the change makes a real medical difference in your case. A lower price by itself does not meet that test.
For FDA-registered medicine-making businesses, section 503B has a separate rule limiting copies of approved medicines.
Ask which kind of business makes your medicine. Have your treating person explain why the change is medically needed in your particular case.
Check the shortage, product and ingredient
At the September 2026 check, FDA’s national shortage list included neither semaglutide nor tirzepatide.
A local stock problem is different from an FDA-listed national shortage.
At the September 2026 check, FDA said adding a vitamin alone does not get around the rule on copies. The person writing your prescription must record how the change makes a real medical difference for you.
Ask which rule the proposed product relies on. A broad claim that copying is allowed is not a full answer.
What “generic” means
A generic is an approved drug that copies a brand-name medicine.
FDA’s guidance checked in September 2026 says it is misleading to call a made-to-order drug a generic version of an approved product or identical to it.
In September 2026, U.S. law allowed no generic version of either semaglutide or tirzepatide to be sold.
For semaglutide, the brand names are Ozempic and Wegovy. For tirzepatide, they are Mounjaro and Zepbound.
Check whether the ingredient is allowed
At the September 2026 check, FDA said federal law did not allow compounding with retatrutide or cagrilintide.
Get the exact ingredient name. An online menu does not answer which rules apply to a particular product.