What you are taking it for and if it has a high potential to deliver the desired outcome. The only reason you would use a separate vitamin B7 (biotin) supplement would be to correct a deficiency diagnosed by a qualified physician. At the same time your doctor can give you any necessary advice on proper use or any individual contraindication. B7/biotin is involved in many important energy producing enzymes and is often recommended for strengthening hair and nails. Little evidence exists that it can deliver on this recommendation unless someone was deficient, which is rare in developed nations. Full biotin deficiency is rare because in normal healthy persons our intestinal bacteria produce it in excess of the body's daily requirements, which are only about 30-100mcgs/day. That said, there are individuals with abnormal metabolism of biotin leading to certain metabolic disorders. In this case they may be treated by a qualified physician with biotin therapy. Biotin sources include Swiss chard, eggs (mainly the yolk), liver, some vegetables and supplements. Most daily multivitamin and mineral formulas (MVM) contain all the biotin necessary (and probably a little more) for normal healthy people. Although biotin deficiencies are rare, marginal deficiencies have been shown in certain populations such as during pregnancy, athletes, dieters, elderly, alcoholics, and burn patients, which can lead to decreased energy production and other biotin related functions. For this reason we always recommend a daily MVM to all populations containing between 100-300mgs of biotin (B7). Active people maintaining low body fat may do better at the higher part of this range.