Last updated: October 2026
Black Friday can be a good time to stock up on supplements you already take and know suit you, as long as you’ll use them before the best-before date. Buy a few months’ supply rather than a year’s, compare the price per serving, and check whether a subscription saves more over the year. Don’t stock up on something you haven’t tried.
This guide covers when stocking up makes sense, how much to buy, how long supplements keep, one-off orders vs subscriptions, and which supplements are worth having in for winter.
When stocking up makes sense
| Stock up if… | Don’t stock up if… |
|---|---|
| You take it daily and it suits you | You’ve never tried it |
| You’ll finish it well before the best-before date | You often forget to take it |
| The saving is genuine compared with normal prices | The “deal” is a different size or strength |
| You have somewhere cool and dark to store it | Your doctor is reviewing your medication |
How much should you buy?
A good rule of thumb is three to six months’ supply. That covers the winter, when many people lean on their evening routine most, without leaving bottles to go out of date. Work it out from your daily amount: a 30-serving pouch taken every evening lasts a month, so three pouches see you to the end of February.
How long do supplements keep?
Always go by the best-before date on the pack. As a general guide, unopened powders, capsules and oils usually keep for a year or more, but once opened they’re best used within a few months. Store them in a cool, dry, dark place with the lid tightly closed, away from the kettle and hob. CBD oils in particular should be kept out of sunlight. See how to store CBD oil.
Doing the maths
Compare the cost per serving or per mg, not the headline discount. Our Black Friday sale, Friday 27 to Monday 30 November 2026, is applied automatically at checkout on one-off orders:
| You spend | You save |
|---|---|
| Up to £49.99 | 25% off |
| £50 or more | 30% off |
| £100 or more | 40% off |
Because the saving grows with your basket, stocking up on two or three months of a product you already use can move you into a higher tier. UK standard delivery is free on every order during the sale. See our Black Friday magnesium and supplement deals. For a worked example of cost per mg, read are Black Friday deals worth it?
One-off orders vs subscriptions
If you take something every day, a subscription can work out better over the year than a one-off stock-up. During Black Friday, Subscribe and Save gives 30% off your first subscription order, then 20% off repeat deliveries. The spend tiers apply to one-off orders and can’t be combined with subscription discounts.
| One-off stock-up | Subscription | |
|---|---|---|
| Best for | A few months’ supply in one go | Products you take all year |
| Storage | Needs space and shelf life | Arrives as you need it |
| Flexibility | Buy once | Skip, pause or cancel |
Supplements worth having in for winter
- Vitamin D: the NHS advises everyone to consider 10 micrograms a day from October to March. See vitamin D in winter.
- Magnesium: a popular part of an evening routine; it contributes to the reduction of tiredness and fatigue. Compare forms in magnesium glycinate vs citrate vs threonate.
- Reishi: a warm, caffeine-free evening drink. See reishi for sleep.
- CBD: if you already use it and know your dose. See CBD dosage.
Check with your GP or pharmacist before starting anything new if you take regular medication.
FAQs
Is Black Friday a good time to buy supplements?
It can be, for supplements you already take and will use before the best-before date. Compare cost per serving and don’t buy something new just because it’s discounted.
How long do supplements last once opened?
Usually a few months. Check the pack, keep the lid closed and store them somewhere cool, dry and dark.
Is it better to subscribe or buy in bulk?
For something you take all year, a subscription spreads the cost and avoids storage. For a few months’ supply, a one-off order in the sale can be better value.
Can I combine Black Friday discounts with Subscribe and Save?
No. The spend tiers apply to one-off orders. Subscriptions get 30% off the first order during the sale, then 20% off repeat deliveries.
Do supplements go off?
They become less effective after their best-before date. Oils and powders can also spoil if stored somewhere warm or damp.
Sources
- NHS. Vitamin D.
