YES. That's was happen to me when I tried Clen. I did only tried for 3 days, I did
Fisrt day
40mcg in the morning, I got big headache also I was sleeping all noon.
Second day
40mcg Clen and Tw Tylenol in the morning, No headache also but got tired.
Third day
40mg Ephedra 400mg caffeine
Fourth day
40mg Ephedra 400mg caffeine
Fifth day
40mcg clen in the morning and 40mcg clen about 4 hours late, also two Tylenol I got no headache, but became very TIRED.
Some have this issue while others do not. Those that do have found that taking the clen dose around 4pm is best. By the time the tired feeling kicks in, it's time for bed.
Clen makes me tired so i usually take around 75% of my daily dose when i wake up then the other 25% later in the day. I get a rush for a couple hours after taking it,that's why i split it up so i get a little pick up later in the evening.
even people that gets lots of energy from clen typically experience periods of deep lethargy and "sleepyness". Often while the hands are still "a shake'in"
I always take clen just before bed.... the main part of the sides are a few hours after ya take it and by morning I don't get the shakes... the headache is only sometimes and it's usually only at the beginning of a course.... and I find it no problem at all to sleep on it when I take it at bedtime... so I might as well sleep through the sides!!