It's the same as the drug store T only it's compounded which basically means that the pharmacy mixes it themselves and can modify the suspension (like sesame versus cottonseed) or the amount in the vial.
Radar is right that how long it lasts will depend on your dosage. But I will tell you one thing. Both vials I've gotten have an expiration 5 months from when you receive it. So it won't last you longer than that.
