In recent years generic versions of finasteride and minoxidil have come into the marketplace. Generics appear when the patent period (typically 15 years) expires for the original company that process/markets a new drug. They are often made in the same facility as the original drug but are generally made by a respected manufacturer in a certified facility. It is worth noting that purchasing generics from overseas manufacturers does not always offer this protection.
The attractive feature of generics is their price as it is usually significantly lower. This reflects the fact that they did not do the original research which is very expensive. Generally speaking, the generics are well produced with equivalent effectiveness compared to the original. Compounding chemists also make variations on original products but the addition of other ingredients is not necessarily helpful.
Many minoxidil hair loss treatment lotions add ingredients such as azelaic acid and retinoic acid. There is NO evidence this increases the effectiveness of minoxidil. Indeed, there is NO evidence that any strength of minoxidil greater than 5% adds to effectiveness.