Diet, high protein low carb low fat. Training for the past 3 years, 18 senior in high school. And I have experimented with clen before. I also go to the gym atleast 4-5 times a week.
Again.
Nope.
Also, how low are these macros? Carbs / Fats? If you are ketogenic, then your proteins (if too high) would put you into glycogenesis and that protein over eating would cause them to be converted into carbs. You need to up the fats my man, and lower the proteins.
You don't need 'Clen', or any other stimulant. You're 18.
Coffee.
When I was 18, I had unmeasurable body fat, and never took anything that was not natural. Coffee, food, sleep, a lot of exercising.
Do not even think about anything non-natural, or steroidal (Clen) until you have past your 25th Birthday, and even then, you'd better think hard and long about that decision. Stay natural, enjoy your life and take your body to it's natural limit.
There is great reasoning behind what I have said, and experience.
Any questions?
PM.