How to store probiotics: a cool, dry place, then the refrigerator

What our labels say

Every PB8 label prints its own storage line, and they are not all the same. The two classic two-capsule formulas, the Original and the Vegetarian, ask for a cool, dry place and say refrigeration is best once the bottle is open. The three 3-in-1 formulas are firmer: store the unopened bottle in a cool, dry place, and refrigerate it after opening. The Immune Support label prints no storage line at all.

If you keep more than one PB8 formula at home, the simplest habit is the strictest one. An opened bottle of any of them goes in the refrigerator door, and the closed bottles wait in a cupboard. You never have to remember which label said "best" and which said "refrigerate".

Why a count is tied to a date

The number on a probiotic label is a count of organisms that are alive. Our labels say when that count was true: "at time of manufacture", and they add in the same footnote that the bacteria count will vary after that day. Other labels on the shelf date their count from the day printed on the bottle instead. Those are two different promises, made from two different days, and it helps to know which one you are reading.

The National Center for Complementary and Integrative Health describes probiotics as live microorganisms intended to have health benefits. Live is the operative word for storage: what the label asks of you is about keeping a living product. The storage line is our instruction for it, and on our bottles it sits right under the footnote about the count.

PB8 Synbiotic 3-1 Probiotic

65 billion CFU, 31 strains, prebiotic fiber. 1 Delayed Release capsule a day.

$39.99$1.33 a day

Neither wording tells you how a bottle was kept after it left the shelf. That part is yours, and it is what the storage line on the label is about.

At home

A cool, dry place means away from the two warm, damp spots most homes have: next to the stove and on a shelf above the shower. A kitchen cupboard away from both, or a bedroom drawer, is fine for a closed bottle. A sunny windowsill is not, however good it looks with the vitamins.

Once a bottle is open, put the lid back on straight after each serving. If the label says refrigerate, keep it in the refrigerator and take the bottle out only for as long as it takes to shake out a serving. The door shelf is the easiest place to remember, and it keeps the bottle at eye level next to the milk you will reach for anyway.

Use the bottle before the date printed on it, and follow one more line from our labels: if the seal under the cap is damaged or missing, do not use the bottle.

Before you buy: size and multi-packs

Storage starts at the shelf. Pick a bottle size you will finish well before its date at the label serving: two capsules a day empties a 60-capsule bottle of the Original in a month and a 120-capsule bottle in two. The larger bottle usually costs less per day, which every card on this site shows, but only if you use it up in time.

Multi-packs of two or three bottles keep the price per day down without leaving one big bottle open for months. Open one bottle at a time and leave the others sealed in a cool, dry cupboard, the place the label asks for unopened bottles. Each sealed bottle starts its own clock only when you break its seal, so the last bottle of a three-pack is as new to you as the first.

At work and on a trip

For a working day, a small pill case with the day's serving is easier than carrying the bottle. Fill it in the morning from the bottle in the refrigerator, and the bottle never leaves home. For a trip, count the servings you need, and keep the case in your bag rather than in a hot car or a checked bag in summer.

The 3-in-1 formulas ask for the refrigerator after opening, so for a long trip it can make sense to start a new bottle when you get home rather than carry an opened one for weeks. A 30-capsule bottle of the Synbiotic 3-1 or the Women's formula is one month at the label serving, which makes it easy to plan: open the next one on the first of the month.

If you would rather not think about the refrigerator at all, look at the classic formulas: their labels make refrigeration after opening the best option rather than a must. The full lineup with every storage line is on the comparison page.

Reading the date and the lot

Every bottle carries a date. On a probiotic it is worth reading twice: once when you buy, so that the bottle will be used up in time at the label serving, and once when you open it. A 120-capsule bottle of the Original is 60 days at two capsules a day, so a bottle bought close to its date may be a reason to pick the 60-capsule size instead.

If you ever need to ask about a particular bottle, the date printed on it is what identifies it. Keep the bottle until it is finished rather than tipping the capsules into another container, and the label, its date and its storage line stay with the capsules. Our guide to reading the label walks through every other line on it.

PB8 Women's Probiotic

50 billion CFU, 27 strains incl. RC-14 and GR-1. 1 Delayed Release capsule a day.

$39.99$1.33 a day

When to ask

If you are not sure whether a probiotic suits you at all, ask a health care provider first. The National Center for Complementary and Integrative Health notes that probiotics have a long history of apparently safe use, particularly in healthy people, and that the risk of harmful effects is greater in people with severe illnesses or compromised immune systems. Take the bottle with you: the storage line and the whole label are on it, and the PB8 strain page lists every strain our labels carry.