"Best time to take supplements" is one of the most searched supplement questions there is, and most of the answers online are either a vague "with food" or a chart with no reasoning behind it. This page gives you the chart and the reasoning, so you can work out the answer for anything not on it.
First, the honest framing: for most supplements, consistency beats timing. A multivitamin taken every day at a slightly suboptimal hour will do more for you than a perfectly timed one you take twice a week. Timing matters a lot for a handful of things — iron, thyroid medication, sleep supplements, caffeine — and only a little for the rest.
The timing chart
Scroll sideways on a phone. "Keep apart from" means leave roughly two hours between them, or four hours in the case of thyroid medication.
| Supplement | When | With food? | Keep apart from |
|---|---|---|---|
| Omega-3 / fish oil | Your largest meal | Yes — needs fat | — |
| Multivitamin | Morning | Yes | Separate high-dose iron or calcium |
| Vitamin D | Any meal with fat | Yes — essential | — |
| Iron | Empty stomach if tolerated | Only if it causes nausea | Tea, coffee, calcium, zinc, thyroid medication |
| Calcium | Split across the day | Yes | Iron, zinc, thyroid medication |
| Magnesium | Evening | Either | Thyroid medication, high-dose calcium or zinc |
| Zinc | Between meals if tolerated | With food if it causes nausea | Iron, calcium, copper |
| NMN | Morning | Either | — |
| Beet root (for training) | 2–3 hours before exercise | Either | — |
| Sleep supplements | 30–60 min before bed | Either | Caffeine, obviously |
| Adaptogens (ashwagandha, maca) | Morning or early afternoon | Either | Check with your doctor if on sedatives or thyroid medication |
| Caffeine / yerba mate | Before early afternoon | Either | Iron supplements, bedtime |
| DIM | With a meal | Yes — fat-soluble | Check with your GP if on hormonal medication |
| Liposomal glutathione | Between meals | No | — |
| Turmeric / curcumin | With a meal | Yes — needs fat | Check with your doctor if on blood thinners |
| Collagen | Any time | Either | — |
| Probiotics | Same time daily | Follow the label | Antibiotics (2 hours apart) |
The three rules behind the chart
Learn these and you can time anything, including supplements we do not sell.
1. Fat-soluble things need fat
Vitamins A, D, E and K, plus oils and oil-based extracts, dissolve in fat rather than water. Take them with a meal that actually contains some fat and you absorb meaningfully more. Take them with black coffee and you waste part of the dose.
This is why our Omega-3 Fish Oil, Pumpkin Seed Oil and DIM pages all say the same thing: take them with a proper meal.
2. Minerals compete with each other
Iron, calcium, zinc, magnesium and copper are absorbed through overlapping transport routes in the gut. Take large doses of two at once and they get in each other's way — iron and calcium being the classic pair.
This mostly matters at high single-mineral doses. The modest amounts inside a balanced multivitamin like Immuno 150 are formulated with that in mind and do not need splitting.
3. Match the supplement to the body clock
Some supplements work with your daily rhythm rather than against it. Sleep supplements are timing signals, so they need to arrive before bed, not at 3am when you have already woken. Caffeine has a half-life of roughly five to six hours, which is why an afternoon yerba mate mix is fine and an 8pm one is not. Beet root works on a delay, so it goes in two to three hours before training rather than at the gym door.
Morning or night?
Morning: multivitamins, vitamin D, NMN, adaptogens, anything caffeinated, iron.
Evening: magnesium, sleep support.
Either, as long as it is consistent: omega-3, collagen, most botanical blends.
If you genuinely cannot remember an evening dose, take it in the morning. A supplement you actually take beats one you time perfectly and forget.
Questions people ask
Should I take supplements on an empty stomach?
Only a few benefit from it — iron and liposomal formulas among them. Most people who take supplements on an empty stomach end up nauseated and stop taking them altogether. We wrote a separate guide on why supplements upset your stomach and how to stop it.
Can I take everything at once?
Usually yes, with the exceptions in the "keep apart" column. If you want the detail, see which supplements should not be taken together.
Does timing change how fast I see results?
Barely. What changes results is how long you have been taking something consistently — see how long supplements take to work, which sets realistic timelines by supplement.
What if I take prescription medication?
Then the chart is a starting point, not an answer. Thyroid medication in particular needs a four-hour gap from iron, calcium and magnesium. Ask your pharmacist — they will check your actual medication list in about two minutes and it is free.
Is it better to take supplements before or after a workout?
For most, it does not matter. The exception is dietary nitrate: beet root peaks two to three hours after you take it, so taking it at the gym door largely wastes it.
Where to start
If you are building a routine from scratch, the foundations come first: see Daily Essentials. Add goal-specific formulas after that — Longevity & Cellular Energy, Sleep, Stress & Mood or Skin & Beauty depending on what you are actually trying to change.
Who wrote this, and what it is not
Written by Daniel, founder of Nutritions Lab. We are a retailer, not a clinic. Nobody here is a pharmacist, dietitian or doctor, and nothing on this page is personal medical advice.
What this guide reflects is standard, widely published absorption and timing guidance — the kind your pharmacist would give you — organised into one place because it is otherwise scattered across a hundred pages. Where the answer depends on your medication, your bloods or your diagnosis, we say so and point you to someone qualified rather than guessing.
Our full approach is set out in our editorial policy, and what we stock and why in our sourcing and quality standards. If you spot something on this page that is wrong, tell us and we will correct it.
When to ask a professional instead
Please speak to your GP or pharmacist before changing supplement timing if you take prescription medication of any kind, particularly thyroid medication, blood thinners, blood pressure medication or antibiotics; if you are pregnant or nursing; if you are giving supplements to a child; or if you have a diagnosed condition affecting your kidneys, liver or absorption.
This article is general information, not medical advice. Supplements are not intended to diagnose, treat, cure or prevent any disease.