Board Thread:Theories and Speculation/@comment-25319479-20171101152711/@comment-27797856-20171101161730

Here's my hypothesis: After the Fourth Shinobi World War, Tsunade studied her grandfather's DNA (We learn that when Naruto was presented with his artificial arm) What if eventually, she found out that Wood Release is not definitively tied to his DNA, but some sort of vitamin/cell structure that Hashirama and the Senju Clan had in their system after centuries of living in woodlands. And Tsunade created a drug that either activated the functions of that structure, or accelerated said functions to the point where they could activate Wood Release in the recipient's body.

I just feel like this has to be tied to biology somehow. This was basically inspired to the Tailed Beast drug that was revealed in the Sakura Hiden.