The first week or or two, the LDN made me sleepy no matter what time of day I took it even starting at 1.5 mg. After that first week, the sleepiness went away for me and then I had extreme insomnia if I took it later than 11 am. I now take it first thing in the morning and hold the liquid in my mouth about 10 minutes for some sublingual absorption. I have learned online that LDN temporarily blocks opioid receptors for about two hours and then the body compensates by producing more endorphins and upregulating opioid receptor production and sensitivity. It is believed that this is why LDN causes pain relief, mood enhancement, and a reduction in inflammation.