I take HGH and IGF-1, the lethargy hits me a short time after taking the IGF not the HGH. I asked Grunt and he said good IGF will do that. I now take in about 75-100grams of carbs with the IGF and slow carbs every 90 minutes after. I was taking IGF twice a day but now only once a day, I felt it was taking too much away from my later workout, on those day I take it PWO.