I had headaches, increased nightsweats and rapid heartbeat when I started testogel 3 months ago. I reduced the dose for a couple of weeks then increased it gradually to 1 sachet a week. This wasn't on any medical advice just my personal decision. Everyone who uses it here seems to be on different doses so I decided it couldn't do any harm to adjust the dose for a while. I haven't had any problems since increasing it again.