Testosterone propionate is definitely not for everyone, however, there are certain men who do benefit from including the ester in their therapy. Propionate needs to be injected more frequently than cypionate, roughly every 2-3 days if used as a monotherapy to keep serum testosterone stable.
For this reason and due to its more robust peak (and trough) effect I personally dont favor propionate as a monotherapy, but it does appear to have anecdotal benefit when combined with a longer ester including cypionate.
Some men benefit from a more robust androgen peak, perhaps those suffering from finsateride syndrome or who have trouble with downstream testosterone conversion. Others who do not metabolize the cypionate ester consistently might also benefit from including lower dosages of shortened ester for faster onset and peak before leveling out.
Again, this is all anecdotal, but it appears that the different effects noticed with a cypionate/propionate blend are experienced with twice per week injections (q3days).
50mg/mL is actually a high concentration of testosterone propionate since roughly 98% of the weight is actual testosterone rather than ester, and its rapid onset and metabolism utilize all of that testosterone over a shorter period of time, resulting in 50mg yielding a higher amount of T than usually produced endogenously.
Usually, less is used as replacement therapy, 12.5mg – 25mg every 2-3 days is the replacement dosage I have seen many doctors start with. Of course, due to fluctuating levels across different patients, prop will need to be titrated more carefully if used as a monotherapy (and more frequent follow ups will be produced at the beginning to ensure levels are not fluctuating from a combination).
Empower’s combination contains 40mg/ml of propionate combined with 160mg/ml of cypionate. It is usually injected at a volume of 1/4ml to 1/2ml 1-3 times per week (10mg-20mg propionate per injection). Since Empower uses grapeseed oil and adjusts the Ph at each batch, I have personally found their propionate does not cause the site irritation that typically results from using other products (due to the propionic acid most likely). I used the blend subq with no issue and have spoken to several guys who reported the same experience.
Another reason this blend might be important is due to access of injectable testosterone options in general. Testosterone propionate products are not available in the US, and therefore testosterone ester blends containing propionate are also not available through commercial products.
This unavailability allows compounding pharmacies to provide these custom options to physicians who then can offer access to patients who benefit from unique formulas and/or need affordable access to cheaper compounded products.
Although compounding pharmacies are justified in compounding testosterone cypionate injectables when using different carriers such as grapeseed oil (vs commercially used cottonseed), the FDA guidance is written with enough flexibility to suppress their ability to make testosterone cypionate products as they could be considered to close to their essential commercial copies (i.e brand name test cyp).
In the event this happens, unique formulas including cypionate/propionate blended products will allow compounding pharmacies to continue providing personalized and lower cost options for men on replacement therapy.