St. John's Wort - does st johns wort cause weight gain?

Hello, no it does not cause weight gain.

St John's wort is generally well tolerated.-

The most common adverse effects reported are gastrointestinal symptoms, dizziness, confusion, tiredness and sedation.

St John's wort may rarely cause photosensitivity. This can lead to visual sensitivity to light and to sunburns in situations that would not normally cause them.Recent studies concluded that the extract reacts with light, both visible and ultraviolet, to produce free radicals, molecules that can damage the cells of the body. These can react with vital proteins in the eye which, if damaged, precipitate out causing cataracts.

Take care and I hope I have been of some help, thank you.-