They are the same molecule, semaglutide, approved at different doses for different indications. Switching is not starting a new drug, but it is not a straight swap either, because the dose strengths and titration schedules differ. Your prescriber decides where you start, and it may not be where you left off.
Do not work out your own equivalent dose. Conversion tables circulate online and they are not a substitute for a prescriber applying the current prescribing information to your situation. Same molecule does not mean interchangeable milligram for milligram across two products with different approved schedules.
For how this fits into the wider titration picture, see GLP-1 Dosing and Titration: The Complete Guide.
Why people switch
Indication. The most common reason. Ozempic is approved for type 2 diabetes; Wegovy for chronic weight management and, separately, cardiovascular risk reduction in certain adults. If the reason you are taking it changes, the appropriate product may change with it.
Coverage. Plans treat them as different products with different criteria and tiers. A plan covering one and not the other is common, and it is a benefit design decision rather than a clinical one.
Supply. Availability of one presentation has at times differed from the other.
Dose range. The weight management product goes higher, which matters if you have reached the top of the other range and further effect is wanted.
What actually changes
The molecule does not. The available strengths, the titration schedule and the pen device do.
Because the strengths differ, there is often no exact match for where you currently are. Your prescriber may place you at the nearest appropriate step, which can mean a small move up or down, then titrate from there.
Expect the device to work differently. Read the instructions for use for the new pen rather than assuming your technique transfers.
What to expect
If your effective dose changes even slightly, side effects can flare briefly while you adjust, in the same pattern as any dose change.
If you move up through new higher doses, expect the familiar sawtooth at each step.
Appetite effects generally continue rather than resetting, since the molecule is unchanged. This is not like switching to a different drug class.
Sort the coverage before you switch
This is where switches go wrong administratively rather than clinically.
Your prior authorization does not transfer. The new product needs its own, under its own criteria, and approval for one says nothing about the other.
Check the new product on your formulary, note whether prior authorization or step therapy applies, and have the request filed before your current supply runs out. A gap mid-switch is the avoidable problem here.
Do not run both
Never take both products in the same period. They contain the same active ingredient, and overlapping them means a much larger amount in your system at once.
If you have supply of both because a switch overlapped, ask your pharmacist what to do with the surplus rather than using it up.
Same molecule does not mean interchangeable, and the coverage difference is explained in why diabetes and obesity coverage differ. Expect a fresh authorization, which is its own process rather than a transfer.
Frequently asked questions
Is it the same drug?
Same active ingredient, different approved doses and indications, different devices.
Do I restart titration?
Sometimes partially, depending on where your current dose sits against the new schedule. Your prescriber decides.
Will my insurance cover the switch?
A separate authorization under separate criteria. Check before switching rather than after.
Can I use up my old pens first?
Ask your prescriber. Do not overlap the two products.
Will side effects come back?
Possibly briefly around any dose change, usually settling as before.
Which is better for weight loss?
The weight management product is the one studied and approved for that purpose, which is why it is the appropriate choice when weight is the indication.