Have you guys ever looked into the various manufacturers. Commercial and compounding? The question is regarding the raws they use. A few of us have noticed there seems to be a difference between brands and it could be completely psychological. Pfizer for example is regarded as being one of the best testosterone manufacturers. Some of the generics are hit and miss and the compounding same thing. I can't figure out if it's a purity thing, quality control thing or if it's just in the heads of myself and some of the guys that I work out with. I was under the impression anytime you see USP printed on a commercial vial it meets at least a minimum quality control standard. I just wasn't sure how often that was tested or how low the standard can get. It's weird because in theory you have the same oils and same preservatives on the commercial side and on the compounding side you have the same product just often in a different carrier oil

Great question, and yes.

In general the commercial products are going to be Depo-Testosterone as a brand name & are all the same. These are just the Testosterone & the carrier oil, which in this case is Cottenseed oil.

When using compounding pharmacies, there are also strict regulations on what counts as compounded. To meet this requirement they may not produce their own depo-testosterone (though they may purchase/resell it), so instead they add in other beneficial compounds, change concentrations, or change carrier oils. As you say this is often Grapeseed oil, though they also have Sesame seed oil. Some will change the concentration down for women or raise it to have it be different. They may add an AI to the mix, add DHEA, or add Test Cyp with Test Eth for example.

When considering generics or compounding pharmacies, the best practice is to look at the size & reputation of the company. We primarily work with compounding pharmacies because they are happy to ship things to patients. We use Empower, Wells Pharmacy Network, AnazaoHealth, and a few others. You can look up their estimated revenue online, and some reach into the 100 million. A company of that size & with a good reputation is one that we would trust to produce quality products. I would be weary of much smaller compounding pharmacies, as there's less oversight the smaller you are, but that doesn't mean all small compounding pharmacies are bad - this is the same advice for small commercial pharmacies.

Outside of all that, each person may react differently to all of these variables which does very much make things subjective. I hope that helps though.