don't buy from the internet! most injectable anabolic steroids sold online come from different countries you are risking them getting picked up by customs. worst case scenario, you come home and the feds are waiting at your door and you go to jail for several years. Not to mention, many of these places sell under dosed or fake products.
IMO, your safest bet is pro hormones that you have thoroughly researched and know exactly what you're putting into your body and the possible long-term side effects. I'd also look into "homebrewing tren".