This is a complicated question. As Gutterpump mentioned, no one knows enough about epistane and the other prohormoes to determine how they will interact with an SSRI. As others have recommended, you may want to consult your physician prior to starting any prohormone. In order to provide you with sounder advice, additional information would be required.
What is your age?
What dose of fluoxetine are you on?
What are you being treated for (e.g,. major depressive disorder, anxiety, etc.)?
Do you have any other medical conditions (e.g., hypertension, hypercholesterolemia, etc.)?
If you are under 30, then the risk of a prohormone like epistane would far outweight the benefits. If you are over 30, on a low dose of fluoxetine for treatment of depression, have no comorbidities, and you feel that your mood may benefit from prohormone supplementation, then you may want to consider starting with a low dose of a prohormone. In any case, you should defer to your personal physician for all medical advice. Hope this info helps.