How should testosterone be stored?
At room temperature, out of direct light and heat. Each product’s label spells out the range:
| Product | Storage on the label |
|---|---|
| Testosterone cypionate vials | 68 to 77°F (20 to 25°C), protected from light |
| Testosterone enanthate vials | 68 to 77°F (20 to 25°C) |
| Xyosted enanthate autoinjector | 68 to 77°F with excursions to 59 to 86°F; do not refrigerate or freeze; keep in carton |
| Kyzatrex capsules | 68 to 77°F, in a dry place away from moisture and humidity |
| Pregnyl (HCG), after mixing | Refrigerate at 36 to 46°F (2 to 8°C); discard after 60 days |
The Depo-Testosterone label gives the cypionate range, the enanthate vial label matches it, and the Xyosted label says plainly: do not refrigerate or freeze. A dresser drawer or closet shelf in a room that stays comfortable year-round works well. Compounded preparations can have their own instructions, so follow the pharmacy label on your vial.
Why does cold cause crystals?
Testosterone esters are powders dissolved in oil. The cypionate label describes testosterone cypionate as a white or creamy white crystalline powder that is soluble in vegetable oils. When the oil gets cold, it can hold less of the hormone in solution, and some of it settles out as visible crystals or a cloudy haze.
The labels anticipate this. The cypionate label notes that crystals may form during storage at temperatures lower than recommended, and the enanthate label says the same about storage at low temperatures. Crystals do not mean the hormone has gone bad, but a dose drawn from a vial with undissolved crystals may not contain what the syringe marks suggest.
How do you safely redissolve crystals?
Gentle warmth and movement. The enanthate label says warming and rotating the vial between the palms of your hands will redissolve crystals, and the cypionate label says warming and shaking the vial should do it.
- Let the vial come up to room temperature on its own.
- Hold it between your palms and roll it for a few minutes, or shake it gently.
- Hold it up to the light and check that the liquid is clear, with no crystals, particles or cloudiness.
- If it does not clear, set it aside and call the clinic or the pharmacy.
Skip the microwave, hot water or a hair dryer; the labels call only for gentle hand warmth. The cypionate label also asks that injectable products be checked for particles and discoloration before every use.
Does heat matter as much as cold?
Yes, for different reasons. Room temperature on the labels tops out at 77°F, and the Xyosted label permits excursions only up to 86°F. A closed car on a summer day can get much hotter than that, so do not leave testosterone in a glove box or trunk. When you travel, keep it with you rather than in a parked car. Our guide to traveling with testosterone covers packing.
What does need the fridge?
Mixed HCG is the main one for men on TRT. The Pregnyl label says to keep the unmixed vial at room temperature, then refrigerate it after mixing and throw away any unused solution after 60 days. Many peptides also have cold-storage rules; our guide to storing peptides and injectables sorts out which is which. The Kyzatrex label keeps oral testosterone at room temperature too.
How Ultimate Male sets you up
When you start injections, your provider reviews storage along with technique, including what to do if a vial gets cold or hot. If anything about a vial looks wrong, such as cloudiness, particles or a color change, call the clinic before you inject rather than guessing.
For related questions, see how long a testosterone vial lasts, whether you can pre-fill testosterone syringes and our comparison of cypionate and enanthate. To start treatment, read about testosterone therapy at Ultimate Male.
