Thymosin alpha 1 is approved for the treatment of HBV infection (

Is thymosin alpha 1 is approved for the treatment of HBV infection in India?..what is chances of hbsag positive clearance and helpful in functional cure??

Dear @Ugyen ,

Yes thymosin alpha 1 (sold as Zadaxin) is approved for the treatment of chronic HBV infection in India. When used as a monotherapy or with NUCs, this drug performs similarly to pegIFN in Asian populations. In European / North American studies, it was inferior to pegIFN.

Functional cure with Zadaxin only occurs in a small fraction of patients with 48 weeks of therapy.

Best regards,


So zadaxin should be taken along with Tenofavir?
Or it should be taken single?.
Is zadaxin apporoved drug by WHO?

Thank you

Hi @Ugyen

The WHO does not approve drugs for use, this is the responsibility of each country’s regulatory body which evaluates the safety and efficacy of drugs. The WHO maintains a list of “essential” medicines which are known to be important for the treatment of diseases with a global impact. For HBV, only ETV and TDF are on this list.

In order to maximize your potential benefit from Zadaxin, you should take the medicine while you are also taking a NUC therapy, preferably TDF. It is important to note that even with this combination, Zadaxin does not really perform any better than pegIFN.

Best regards,

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It is worthwhile to get opinions from your health professional to make sure that Zadaxin is not going to interact with any other medications or health conditions that you have, as well as make sure that it is likely to benefit you (relative to its potential side-effects).