So, you just got that cool box of Thorne supplements. You open it, you take out your new supplements, and you are all set to take your health routine to the next level.

At Thorne, we take great pride in making exceptional nutritional supplements, with well-tested ingredients and minimal excipients. But it’s not just about what we’re doing; the way you are storing vitamins and other supplements in your home will also impact supplement quality.

Do vitamins expire? Although nutritional supplements are not food, they are similar when it comes to the topic of storing vitamins; once the bottles are opened and exposed to light, air, heat, and moisture, they can begin to degrade – some faster than others. 

When we seal the bottles in our manufacturing plant, it is done in a highly controlled environment. We strictly regulate temperature and humidity, and we ultra-filter our air to ensure perfect conditions.

We certainly don’t expect you to have these conditions at home. You should take note that our labels say, “Store tightly sealed in a cool, dry place” – but what does that mean?

While “cool” means different things to different people, for most supplements it usually means a range of 68-77 degrees Fahrenheit, which is the same for most prescription medications. Some temperature variation shouldn’t be a problem, and colder temperatures probably won’t have much impact at all. Instead, it’s higher temperatures that can cause supplements to degrade more rapidly than normal.

Humidity, a measurement of how much moisture is in the air, is another issue. Generally, if you live in the Southwest, humidity is going to be low; but if you live in the Southeast, humidity can be close to 90 percent in the summer. 

“Dry” for supplements typically means below 65 percent relative humidity. So, depending on where you live, humidity can be more or less of a challenge on how you store your supplements.

When supplements are exposed to humid conditions and absorb moisture, they tend to get clumpy or have dark spots. Although this does not ruin a supplement’s efficacy, it does shorten its shelf life, and it certainly makes them less visually appealing.

Six storage tips

1. The bathroom is probably not a good place, even though that’s where the medicine cabinet usually is. In most homes, the bathroom is the most humid place because what we do there – showering, washing our hands, brushing our teeth – involves water. That’s why most bathrooms have a built-in fan.1

2. The same holds true for the kitchen. Compared to other rooms in your home, your kitchen probably undergoes more changes in heat and humidity than other rooms.1

While a kitchen cabinet can be a good choice, stay away from the areas near the stove, oven, or sink. Should you be storing vitamins in the fridge? Good question. Your refrigerator, while cool, can have unpredictable humidity levels depending on how often you open it. If you should be storing vitamins in the fridge, then it will state it on the bottle. Currently, the only Thorne supplement that requires refrigeration is our Omega Superb liquid fish oil, which should be refrigerated after opening.

3. Reclose bottles tightly. The plastic that our bottles are made of is designed to protect the product inside. Making sure the lid is on securely optimizes that protection.

We test the stability of our products in their original packaging, so we know that our bottles keep out light, air, and moisture. While pill boxes and bags are convenient for organization, we recommend you reserve them for travel and other short-term use, but not for storage.

4. Keep the little desiccant packets in the bottle after you open it, especially if you live in a humid location. The desiccants absorb moisture and are especially important for protecting ingredients that are prone to absorbing moisture. The more likely an ingredient in the product is to absorb moisture, the more desiccant packets we include in the bottle. Although it is a little more work to get the capsules out of the bottle, the capsules will hold up better if you leave in the desiccants.

5. Find a cool, dry place with good air circulation. For a lot of homes this is in the bedroom. We often more tightly control temperature and airflow in the bedroom because it makes sleeping more comfortable. A nightstand drawer, for example, can be a good place for supplements you take in the morning or at bedtime and is probably a better environment than the bathroom. The pantry (or wherever you store spices, baking goods, grains, or cereals) is often a good choice because the conditions needed to store those items are similar to what is ideal for supplements. 

6. Do vitamins expire? Yes, that’s why you should always pay attention to expiration dates. At Thorne, we do stability testing on all our products to validate the expiration date. But if you’ve had your health solution for a long time and it’s past its prime, how do you dispose of expired vitamins? Regardless of how you store a Thorne supplement, even if you have never opened it, we suggest you discard it if it is past its expiration date. 

A final word

Sometimes bad luck just happens. Maybe you got a package delivery while you were out of town and your supplement froze on your front porch or sat in 95-degree weather in your mailbox.

Maybe the delivery person got a little too aggressive delivering the box and the seal on a bottle is damaged. If something doesn’t seem right or you are unsure, you can always get in touch, and we will help you sort it out.

Reference

  1. Purdue University. Vitamins stored in bathrooms, kitchens may become less effective. ScienceDaily 2010. www.sciencedaily.com/releases/2010/03/100302162257.htm [Accessed Jan. 17, 2025]