Her husband is weak – can she put medicine in his food without him knowing?

I am a woman who needs intimacy with my husband, but my husband is weak in this regard. I have tried to convince him to get treatment but with no success. Can I put medicine to strengthen his desire in his food without him knowing?.

Praise be to Allaah.  

I asked our Shaykh ‘Abd al-Rahmaan al-Baraak about this and he replied: 

She should not do that. If she cannot put up with it she may ask for a divorce.