Unfortunately my friend took several of these pills thinking they were methadone which he takes regularly. Now he can't sleep and he is feeling extremely anxious. I have searched for several hours and the only thing I saw was a skin whitening pill or supplement called Glutathione coming from the Philipines but when I clicked on link there was no further information. My friend asked pharmacist and he was at a loss as well. Can anyone help? The pill is white, oblong with a hatch mark and N623 on front. Thanks.