Can the patent protection period be extended?

You can't. According to Article 42 of the Patent Law, the term of the invention patent right is 20 years, the term of the utility model patent right is 10 year, and the term of the design patent right is 15 year, all of which are counted from the date of application.

Because patent right is a very exclusive right, if the law allows it to extend the term of patent protection, it may lead to monopoly, which is not conducive to scientific and technological progress and thus harms the public interest. Therefore, according to the relevant laws and regulations, the patent right cannot be extended after its expiration, which leads to the extinction of the patent right.