Clinical studies demonstrate that topical Finasteride has clinically proven, evidence-based, scientific data to show its efficacy in growing hair and that it may have a lower side effect profile compared to oral Finasteride. There are many side effects associated with oral Finasteride, especially sexual side effects. There have been many clinical studies on topical Finasteride. Majority of those studies showed no sexual side effects for patient using topical Finasteride, sometimes at higher concentration than our formula. Specifically, out of the 7 clinical studies reported above, only one study showed one event with sexual side effects (testicular pain). This is 1 out of 268 subjects in all of the studies. In contrast, oral Finasteride is associated with sexual side effects in 1.8% to 3.8% of patients. One should be aware that side effects may still occur even with topical Finasteride and it is recommended to titrate up the use of topical Finasteride in order to avoid shocking the system and our Doctors will go over that with you. Please remember that any side effect that may occur on oral Finasteride can possibly occur with topical Finasteride, but according to clinical studies, the side effects may be lower. Please note that patients may have different sensitivity to the topical Finasteride, thus results and side effects may vary. Please consult with a Doctor before starting prescription strength topical Finasteride. In the case of Happy Head, you will have a free consultation with a Doctor in order to determine eligibility for the topical Finasteride. Eligibility is based upon medical history, current degree of hair loss, allergies etc. Your Doctor will also review side effects with you in writing. We encourage our users to read our blog titled “Side Effects of Topical Finasteride: Review of Current Medical Literature.” Please note that the information above does not constitute medical advice and should only be used for informational purposes only. The information is not a substitute for professional medical advice and please do not rely on this information to make medical decisions. Please make sure to discuss the risks and benefits of any treatment with your medical Doctor before beginning treatment.