I heard testosterone levels should be between 300-1100. is this true?

Yes: But it depends on the lab. Testosterone is secreted more in the am.

True: Most labs report that the reference normal range for a morning total testosterone level should be between 300ng/dl - 1, 100ng/dl. The relationship of that range with age is inverse. A 30 y/o male's average level is about 675ng/dl while the average level for a 85 y/o male will approach 300ng/dl. If you have symptoms and your level is around 300ng/dl, you may benefit from a trial of therapy.