Again, do your own research, but for best results, research shows that L-arginine should probably be taken separate from most other supplementation for best results, as certain supplements will interfere with the absorption of L-arginine, however, L-Citrulline has been shown to boost nitric oxide production when used in conjunction with L-arginine and research shows the levels should be from 200-1000mg per 5000mg of L-arginine. L-arginine is best taken on an empty stomach and not eating for an hour of two after taking; if you must eat, avoid proteins in this time period. If you get an upset stomach or diarrhea (these are very rare) when taking L-arginine, you may take some carbohydrates to help prevent this. Do not take less than 5 grams in a dose (5,000mg) as it may not give you the results you seek. For most people, the most likely time to take it would be right before bed or upon first awakening. If you are going to take double or triple doses you will have to do some advance planning to spread it into individual 5 gram doses throughout the day. Although taking 10 or 15 grams at one time will not likely harm you, it won't likely be as effective as separating them into individual 5 gram doses. Another tip some have found useful is to take a dose in the middle of the night if you generally have your sleep interrupted by a need to urinate.