Nowhere. You need a prescription. Do not buy online as the "legit" companies often lie and you can land yourself in the hospital from the false advertising. There is a reason things are prescription only and hence there is a real danger of buying things online. The only other option to increase estrogen would be to eat foods with trace amounts of estrogen based substances, but that would require eating an absolute ton because the levels are in the extremely minute molecular amounts. But that said having estrogen levels within the acceptable amounts based on blood work is perfectly okay. If the levels were very very low then the doctor would opt for estrogen supplements but when you are in the normal range there really is no need to as your body can create more if it needs more to balance things out (providing there is no diagnostic reason for the inability to produce more estrogen to the required levels).