Short answer
- No. Store nitroglycerin at controlled room temperature, 20 to 25°C or 68 to 77°F.
- Refrigeration introduces condensation every time the bottle comes out, and moisture degrades nitroglycerin.
- The fridge also puts your rescue medication somewhere you aren't.
- Keep it out of the bathroom too. Heat plus humidity is the worst combination for this drug.
- A bedroom drawer, or a sealed holder you carry, is better than either.
Short piece, because it's a short answer, but the reasoning is worth having.
What the label says
Nitroglycerin is stored at controlled room temperature. The Nitrostat label puts it at 20 to 25°C, which is 68 to 77°F, and that's the same standard that appears on most prescription medications. Brief excursions between 15 and 30°C are permitted, which covers a warm afternoon or a cold entryway.
There is no version of the guidance that recommends refrigeration.
The labelled storage range, and everyday temperatures
See the numbers
| Where | Temperature | Against the range |
|---|---|---|
| Parked car in summer sun | 120°F and above | Far above |
| Body temperature | 98.6°F | Above |
| Storage range on the label | 68 to 77°F | In range |
| Refrigerator | About 40°F | Below |
Why cold is a problem, not just unnecessary
The intuition behind refrigerating medication is that cold preserves things. For a drug whose main enemy is heat, it seems to follow that colder is safer.
The problem is what happens when you take the bottle out. A cold bottle brought into a warm room collects condensation on the glass, and when you open the cap, moist warm air moves into a cold container and condenses inside. Do that daily and you're introducing water to a medication that degrades in the presence of moisture.
Humidity is one of the two things that damages nitroglycerin, alongside heat. Refrigeration trades a problem you might not have for one you're creating on purpose.
There's a practical objection too, and it might be the more important one. Nitroglycerin is a rescue medication. Its entire value is being within reach in the ninety seconds when you need it. A bottle in the kitchen fridge is a bottle you have to walk to, and if the reason you need it is chest pain on the stairs, the walk is the problem.
The bathroom is worse
If refrigeration is the wrong answer, the medicine cabinet in the bathroom is the more common wrong answer, and it's worse.
A bathroom during and after a shower produces high heat and high humidity at the same time, repeatedly, every day. That's precisely the combination that showed the fastest degradation in stability testing. It's a strange quirk that the cabinet built into most American bathrooms is called a medicine cabinet, because it's close to the worst room in the house for storing medication.
Where to actually keep it
A bedroom drawer or a closet shelf is fine. Dry, dark, stable temperature, no shower steam, no radiator.
Where to keep it
Better
- Bedroom drawer
- Sealed holder you carry
Worse
- Bathroom cabinet
- Glove box
- Sports bra
- Plastic baggie
For the bottle you carry, the honest answer is that no pocket-sized container is temperature-controlled, and anyone selling you one is overstating things. What a sealed metal holder does is keep water out and put a layer between the bottle and your body heat, which matters because how you carry it is a documented factor in how long it lasts. Our Wide Single Chamber holder is built around a standard 25-count bottle for exactly that.
If you're going somewhere genuinely hot for an extended period, put the bottle in a bag rather than against your body, and keep it out of the car.
Questions people ask
I've been keeping mine in the fridge. Is it ruined?
Not necessarily, and it depends how long and how often you opened it. Ask your pharmacist. Going forward, move it to a dry drawer at room temperature.
What about the freezer?
No. Same condensation issue, more extreme, and freezing isn't in any storage guidance for this medication.
Does nitroglycerin spray have different storage rules?
It does, and they vary by product. Sprays and patches have their own labels. This article is about sublingual tablets.
Is a car glove box ever acceptable?
Not in summer. Parked car interiors routinely exceed 50°C in direct sun, well beyond the permitted range. In mild weather it's less dangerous, but a glove box is still a place your medication isn't when you're out of the car.
Educational information, not medical advice.
Sources
Nitrostat FDA label ·
Mayo Clinic ·
Cleveland Clinic ·
Nawarskas et al., Am J Cardiol 2018