Hello! N-acetyl cysteine have side effects that concern the bronchial and pulmonary function, it may cause bronchispasm, chest tightness and hemoptysis (blood from the lungs), vomiting, stomatitis etc. It s use is contraindicated in bronchial asthma. Biotin is a natural component. It s use has reported no side effects in recomended doses. Many side effects may occur during the use of finasteride and in some cases the disorders may not disappear after the discontinuation of the drug. The most frequent adverse effects are dysfunction of erection and sometimes of ejaculation too, decreased libido, breast tenderness and enlargement. Another effect has been reported, male infertility with poor seminal quality, but it has become normal after the discontinuation of the drug. I hope i have been of help.