"Healthy robust 53 year old here....50mgs work great but on an empty stomach. Slower and less effective on top of food. Reaction within 30 minutes with better erections up to 9 hours later. Side effects. Nasal congestion, flushing fullness in head, eye pressure, sometimes increased heart rate and respiration. Poor sleep, next day fatigue and slight anxiety. I went crazy with this when I first started and took it every day for a week. Lots of fun. But it completely wore me out. No, it wasn't all the sex. It really does affect you in a negative way with too much use. I find increased side effects if I take it near the time of thyroid medicines. I take it once a week or so and it's worth the side effects."