A shelf life is the period in which a material is expected to stay within its specification, provided it is stored as stated. A retest date is not an expiry date: after a retest date the material is examined again before use, while after an expiry date it should not be used. Each depends on the day the period starts, the storage conditions and the packaging.
An extract specification often ends with two short rows: a shelf life or retest period, and a storage statement such as “store in a cool, dry place”. They are easy to read as formalities. They bear on how long you can hold the material, how you have to keep it and what you may do once the date has passed.
Here are six checks to make on these rows. They draw on two international guidelines for medicines and their ingredients, on European guidance for medicines and for herbal medicines, on European Union food law and on the United States rule for dietary supplements. Our earlier articles covered the specification, the extract ratio, the Certificate of Analysis, the solvent and carrier, the heavy metal and pesticide rows, the assay method, the microbiological rows, the identification row and the physical rows; this one stays with the dates and the storage statement.
01 / THE DATE
Is it an expiry date, a retest date or a best-before date?
A row headed “shelf life” can stand for three different kinds of date. Good manufacturing practice guidance for pharmaceutical ingredients keeps two of them apart. An expiry date marks the time during which such an ingredient “is expected to remain within established shelf life specifications if stored under defined conditions, and after which it should not be used”. A retest date is the date “when a material should be re-examined to ensure that it is still suitable for use”. For pharmaceutical ingredients, the guidance adds, “common practice is to use a retest date, not an expiration date”.1
European Union law on food information to consumers has a third kind. The best-before date, in the law’s words the “date of minimum durability”, is “the date until which the food retains its specific properties when properly stored”. Only for foods that are highly perishable from a microbiological point of view is it replaced by a “use by” date, after which a food is deemed to be unsafe.2
The three do not mean the same once the day has passed, as the sixth check shows. A row that gives only a number of months does not say which of them it is.
Check: which kind of date the row gives: an expiry date, a retest date or a best-before date.
02 / THE START
From which day is the period counted?
A number of months means little until you know the day it is counted from. For the batch you are offered, the Certificate of Analysis should show the date itself: the same guidance asks for an expiry date to be shown on the label and the certificate, and a retest date on the label, the certificate or both.1 Our article on the Certificate of Analysis lists the dates to look for there.
Ask which day counts as the date of manufacture. For an extract several days are candidates: the day of extraction, of drying or of blending. Where batches have been blended, the guidance lets the earliest material decide: the expiry or retest date of a blended batch “should be based on the manufacturing date of the oldest tailings or batch in the blend”, tailings being small quantities of material from batches of the same product.1
What matters to your planning is the time left when the goods arrive. A batch made in January and delivered in March of the following year has already used about fourteen months of its period, whatever that period is. If your production plan and the date on your own product need a minimum remaining period, say so when you enquire.
Check: the day the period is counted from, whether the batch is a blend, and how much of the period will be left on delivery.
03 / THE CONDITIONS
Under which storage conditions does the period hold?
Each of these periods is conditional. The international guideline on stability testing of medicines defines a re-test period as the time in which a substance “is expected to remain within its specification”, and adds: “provided that the drug substance has been stored under the defined conditions”.3 The food information law attaches the same condition to the best-before date: the food keeps its properties “when properly stored”, and the date is followed, if need be, by “a description of the storage conditions which must be observed if the product is to keep for the specified period”.2
So the storage statement deserves as much attention as the period. The stability guideline wants it “based on the stability evaluation” and says that terms such as “ambient conditions” or “room temperature” should be avoided.3 European guidance on how storage conditions are declared for medicines is blunter: the use of such terms “is unacceptable”, and the conditions “must be possible for the user to follow”.4
In that guidance a table ties each statement to the test conditions at which the product was shown to be stable: “Do not store above 25°C” or “Store below 25°C”, for instance, is the statement for a medicine shown to be stable at the long-term condition of 25°C and 60% relative humidity but not at the warmer conditions in the table. The same principles, it says, “should also form the basis for storage declarations of active substances”.4 A phrase such as “store in a cool, dry place” names neither a temperature nor a humidity. Ask for the figures behind it: the highest temperature, the humidity if it matters, and whether the material has to be kept from light.
Storage does not begin in your warehouse. The pharmaceutical guidance asks that special conditions for transport or storage be “stated on the label”.1 The stability guideline wants the conditions and lengths of its studies to be “sufficient to cover storage, shipment, and subsequent use”.3 Time in transit and on a loading bay is part of the storage history of a batch.
In the United States the rule for dietary supplements obliges a supplement company to hold its components “under appropriate conditions of temperature, humidity, and light so that the identity, purity, strength, and composition of the components and dietary supplements are not affected”.5 Ask the supplier what those conditions are.
Check: the temperature, humidity and light conditions the statement means, in figures, and whether they also apply to transport.
04 / THE PACKAGE
In which packaging, and what once it is opened?
A period is established for a material in a particular packaging. Under the stability guideline, studies should be carried out on material packed in a container closure system “that is the same as or simulates the packaging proposed for storage and distribution”.3
Packaging and storage statement work together, and neither replaces the other. “A storage statement should not be used to compensate for inadequate or inferior packaging”, the European guidance says.4
The period on a specification speaks of the container as it was supplied. Once it is opened, the powder meets the air of your own store. For food sold to consumers, European Union law deals with the time after opening as a question of its own: where appropriate, “the storage conditions and/or time limit for consumption” after opening are to be indicated.2 For medicines sensitive to moisture, the European guidance offers the statements “Keep the container tightly closed” and “Store in the original package”.4 Our article on the physical rows explains why a powder that absorbs moisture easily may not keep its loss on drying figure once its packaging has been opened.
So ask what the period assumes: which container, and unopened. If you will draw from one container over several months, ask how it should be closed and kept between uses.
Check: the packaging the period applies to, and how the material should be kept once the container has been opened.
05 / THE EVIDENCE
What stands behind the period?
A shelf life is a statement about the future, and it should rest on data. The pharmaceutical guidance says that an expiry or retest date “should be based on an evaluation of data derived from stability studies”.1
Dietary supplements in the United States are handled differently. The rule requires no expiry date: it speaks of a shelf life date only “if shelf life dating is used”.5 In the explanation published with the rule in 2007, the Food and Drug Administration recalled that in 2003 it had been unsure whether generally available methods existed to set expiration dates for dietary ingredients other than some, such as vitamin C, “especially botanical dietary ingredients”. It repeated that any expiration date placed on a product label, a best-if-used-by date included, “should be supported by data”.6
For an extract there is the further question of what was followed over time. European guidance for herbal medicines regards the herbal preparation “in its entirety” as the active substance. Where the constituents that account for its activity are not known, it says, “simply determining the stability of active marker(s) or analytical marker(s), will not suffice”: a series of tests that can show change is needed, and the stability of the preparation as a mixture should, as far as possible, also be shown, for example by “appropriate fingerprint chromatograms”.7
The same guidance shows what a period promises about the content. Where the constituents that account for a preparation’s activity are known, their content must meet the release limit throughout the stability study. Where they are not, the guidance accepts a change in marker content of ± 5% from the batch’s initial value, and possibly ± 10% if justified.7 It sets a limit all the same: active markers, those generally accepted to contribute to the activity, have to remain within their defined ranges at the end of the retest period or shelf life, and analytical markers, used for analytical purposes, should “remain within the release acceptance criteria, unless otherwise justified”.7 For finished medicines the stability guideline allows “justifiable differences between the shelf life and release acceptance criteria”.3 So ask whether the limits on a specification apply at release or until the end of the period.
It also matters which rows were followed. The stability guideline expects an evaluation to cover “not only the assay, but also the levels of degradation products and other appropriate attributes”.3 Our articles on the microbiological rows and on the physical rows describe two results that can move in storage: the microbial counts and the moisture.
So ask what the period rests on: a study of this extract in this packaging, data on a similar material, or experience with the product. The row alone does not say which.
Check: what the period is based on, which rows were followed over time, and whether the limits apply at release or until the end of the period.
06 / AFTER THE DATE
What may be done once the date has passed, and what does it mean for your own product?
A retest date is not the end of a batch. Under the stability guideline, a batch that has passed its re-test period “should be re-tested for compliance with the specification and then used immediately”, and it “can be re-tested multiple times and a different portion of the batch used after each re-test, as long as it continues to comply with the specification”.3 For the retest the pharmaceutical guidance asks for “a representative sample”.1 An expiry date leaves no such way open: after it the material “should not be used”.1 A best-before date is different again: it is the date until which a food keeps its specific properties, and it is after a “use by” date, not a best-before date, that the law deems a food unsafe.2
Whether an extract past its date can be retested therefore depends on the kind of date the supplier has given, and on your own quality system. If the row gives a retest date, ask which tests a retest should cover and by which methods, so that the new results can be set beside the Certificate of Analysis.
The date on your own product is a separate decision, and it is yours. In the European Union the business responsible for the information on a food, its best-before date included, is the operator “under whose name or business name the food is marketed”, or the importer where that operator is outside the Union. A business that supplies other businesses with food not meant for the final consumer must give them “sufficient information to enable them, where appropriate, to meet their obligations”.2 In the United States, as the fifth check showed, the agency’s stated view is that a date on a supplement label should be supported by data.6
The ingredient’s period is one input to that decision. It tells you how long the extract was expected to keep its specification in its own packaging; it does not tell you how the extract will behave in your capsule, tablet or drink.
Check: what may be done after the date, which tests a retest should cover, and what the date on your own product will rest on.
WHAT TO SEND
State your shelf life and storage requirements with your enquiry
When dates and storage matter to your planning, tell us:
- the ingredient, and the plant part if more than one is offered;
- your intended application and destination market;
- the remaining shelf life you need on the day of delivery, and your target delivery date;
- the conditions under which you will ship and store the extract, in figures where you have them;
- your packaging needs, and whether you will draw from one container over a longer time;
- whether you will test the delivery yourself, and by which method;
- which technical documents you need, such as a specification sheet or Certificate of Analysis;
- your name, company and contact details.
We offer technical documentation and COA support, and the available document set is confirmed for each ingredient and project. Specification ranges in our catalogue are references, and feasibility, availability and price are confirmed with your quotation.
This article describes published guidance and law and gives no shelf life, retest period, storage conditions or packaging for YOHOLIFE® ingredients; the specification and documents for a selected grade are confirmed when you enquire. Sources 1, 3 and 4 were written for medicines and their ingredients and source 7 for herbal medicines; they are cited here for their definitions and approach. Source 3 is under revision: a draft of a combined guideline was released for consultation in 2025, and the version cited is the adopted one. Source 2 is European Union law on food information to consumers. Great Britain has its own versions of the food rules cited, which are not covered here. Source 5 is United States law, and source 6 is the explanation published with it in 2007. Sources were checked on 13 November 2026 and are given for orientation, not as regulatory advice.
