Logged in half an hour ago and had full energy, took a xanax and a FHC only to find that my energy hadn't gone up to the 450/550 (can't remember exactly since it's been a while since I've played actively) but instead was still at 100.
Don't know if anything changed with the FHC's but the xanax should have added 250 e to my already full bar of energy. I have the cooldown period of both items I took.
Logged in on my mums laptop and won't be on it for long enough for a screenshot so apologies for that.