Most pharma grade test cyp has a "use by" date on it that's about three months after it was manufactured, which I suspect is mainly to keep people from stockpiling it for later use. How long would you estimate the oil is really good for, assuming it's kept in a dark, room temperature environment?
I have always heard that there is what's known as a "peak" test shelf life but even with the expiration date I believe the shelf life has gotta be atleast over a year. But I could be wrong. They do add a lot of preservative to keep the hormone sterile.
Here's what I found for you.
Testosterone Cypionate Shelf Life
Many men are now self-injecting testosterone cypionate as part of their HRT program and find themselves, for one reason or another, with expired vials. And they wonder if it is safe to use this "old" testosterone cypionate. Of course, I encourage men to play it safe and go by the expiration date for a variety of reasons:
1. Lack of Preservatives. Cypionate from one of the bigger pharmaceutical manfacturers will tend to have a pretty long expiration date. However, some of the compounding pharmacies' expiration will be much shorter and this is for a variety of reasons. One of them is that, at times, they deliberately do not put preservatives in their preparations. Regardless, it is best to play it safe and respect their judgement as to how long they think their preservative, or lack thereof, will last.
2. Oil Breakdown. Testosterone cypionate is in an oil base and, while the ester itself is very stable, the oil itself can break down even more quickly. Only the manufacturer knows the shelf life of their oil preparation and so it is best to heed their analysis. For example, some will be stored in sesame or cottonseed oil. And castor oil will, I believe, last even longer. Again, only the manufacturer knows all the details of their oil product.
NOTE: It is possible, although rare, to have an allergic reaction to the oil itself. Discuss with your doctor if you think this an issue for you.
3. Loss of Efficacy. From what I have read, testosterone cypionate is a stable molecule. Furthermore, hormones do not tend to break down into harmful byproducts. But, that said, any loss of efficacy is not good for your testosterone therapy program and, unfortunately, the manufacturers do not have to release degradation rates. So only they know how rapidly their product will break down and so you are left guessing.
If you knew better, you'd do better! Knowledge is power!
