Tweetyou have to know your stuff going in. if you are married and or have kids, you have to tell the doc that you are concerned with cross contamination. no doc in his right mind will give you a gel with women and kids in your house. on the other hand i know one old dude that gel is all he can use. well he went the gel route because his hair was falling out really bad with inject at 3 different doses. when they switched him over to gel his levels stayed where they wanted and his hair stopped failing out. he is an old fat dude and i am pretty sure only reason why he went on was to keep mr happy working though