I'm 20yrs old, 89kg & 170cm, prescribed 40mg duromine, will this make me anxious? is it dangerous? is there a high probability of side effects?

Nervousness: Phentermine, also marketed with the brand name Duromine, is an appetite suppressant which has a good track record of safety and usefulness. The most common side effects are similar to caffeine- nervousness, palpitations, insomnia, and many people also get dry mouth and constipation. Because, like all drugs, there are occasional more severe side effects, it should be used only if really necessary