Injectable l carnitine has 100% bioavailability and its a supplement, not steroid., Even as a natty you can use and it can also help you in your bulking process, not just in fat loss. , ., Baaki if Skinny Shot Injection L Carnitine Injection: Maximize Fat Burning, Energy & Metabolism L carnitine supplements bioavailability is very less and according to some studies it takes 8 to 12 weeks for for loss results, so if you decide to supplement with oral L carnitine