Ever-greening of patent, as the name suggests, is a corporate, legal, business, and technological strategy for extending / elongating the term of a granted patent in a jurisdiction that is about to expire, in order to retain royalties from them, by taking out new patents.

A patent is a monopoly right given exclusively to an inventor for a limited period of time in return of his/her disclosure of an invention that is a new, nonobvious, and useful product and/or process.

In India, patents are granted for a maximum term of 20 years (provided it is maintained by paying annuity fees). After the expiry of the patent, the invention goes into the public domain which is free for use, manufacture, sell, or import. However, sometimes the patentees (mostly pharmaceutical companies) attempt to extend this monopoly right beyond the limited period of 20 years. When the term of the patent is about to end, these companies make trivial /insignificant variations to the existing patented invention and file for a new patent, thus extending their monopoly. This is known as the Ever-greening of a patent.

Let's understand Ever-greening with a simple example:

Auppose, a patentee XYZ is granted an ordinary patent "X" for his/her invention in India which was filed in the year 2010. So, the granted patent "X" will expire in 2030. Now, the patentee does minor modifications in the invention in patent "X" and files a new ordinary patent "Y" application in India in the year 2028 before the expiration of patent "X" (which is 2030).

Assumptions in this case:

  1. The new patent application "Y" qualifies the basic patentability criteria i.e. the invention is new, comprises inventive step, and has industrial applicability.
  2. The minor modifications do not change the general structure of the invention disclosed in the specification of patent "X" but are related to minor changes in composition, for example replacements of isomers/reactants used in the invention of patent "X".

Now, if suppose a patent "Y" is granted as a new ordinary application, the granted patent "Y" will expire in the year 2048.

From this, we can see that the invention for which the patent was scheduled to end in the year 2030, and would have come in public domain; through ever-greening it, the applicant/patentee managed to extend the life of his patented invention by 18 more years. This is the basic idea of ever-greening.


Sometimes generic products are available in the market once the patent expires. With these generic products from different companies, competition in the market sets in. This results in the lowering of the price of the product. Ever-greening of patents does not allow the price of a product to come down due to the extension of the patentee's monopoly.

In India, section 3(d) of the Patent Act, 1970 states that the "mere discovery of a new form of a known substance which does not result in the enhancement of the known efficacy of that substance or the mere discovery of any new property or new use for a known substance or of the mere use of a known process, machine or apparatus unless such known process results in a new product or employs at least one new reactant", is not patentable under the Indian Patent Act.

Section 3 (d) incorporated in the Patent Act initiates the resistance to the ever-greening of patents. Hence, the ever-greening of patents is not easily obtained in India (in contrast to many other countries).

However, the positive aspect of blocking patent evergreening is that it brings relief for poor patients who depend on life-saving drugs. It also helps in keeping the price of essential drugs within the reach of common people in developing and underdeveloped countries.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.