The patent covering semaglutide, the active ingredient in Ozempic, has expired or been invalidated in several countries including India, China and Brazil. In Mexico it remains in force.
This is not an inconsistency. It is the basic architecture of the patent system: protection is territorial. A patent grants exclusivity only in the country that issued it, for the term that country recognizes, subject to that country validity challenges. There is no such thing as a worldwide patent.
Why the same molecule has different fates
Filing dates differ by country. So do the rules on what counts as an inventive step, whether second medical uses are patentable, and how aggressively local generic manufacturers litigate. A patent can be revoked in one jurisdiction for lack of inventive step and survive in another on the same prior art.
The commercial consequence is visible on the shelf: generics appear in one market while the originator keeps exclusivity, and pricing, in another.
What this means if you are an inventor
Decide early where you actually need protection, because you cannot fix it later. The Patent Cooperation Treaty buys you thirty months from the priority date to choose national phases, but it does not create rights on its own. Filing in Mexico only, and then discovering your product sells in Colombia, leaves you with nothing there.
Map your markets before the priority year runs out, and budget for the countries that matter commercially rather than the ones that are cheapest to file in.
The clock on every patent
A Mexican patent runs twenty years, non-extendable, counted from the recognised filing date, and it is subject to payment of each annuity (article 53 of the Mexican Industrial Property Law). There is no renewal at the end. When the term expires the invention enters the public domain and anyone may use it, which is the whole bargain: disclosure in exchange for a limited monopoly.
Two consequences people underestimate. The annuities are a live obligation, and a granted patent that stops paying them lapses long before its twenty years are up. And because the term runs from filing, not from grant, every month spent in examination is a month of monopoly already consumed.
If the invention is one you would rather never disclose, the alternative is to keep it a trade secret, which has no expiry at all but no certificate either, and which depends entirely on the measures you took to keep it confidential.