How to build a supplement routine that works for you

In our 2025 Annual Health Survey we asked 940 of you which health trends you had tried.

The most popular health trend? Magnesium supplements.

Two thirds said that you had tried magnesium supplements. It was the most popular health trend by far, surpassing cold baths, red light therapy, collagen, and even the ever-popular high-protein diets.

It’s great that people are taking control of their health – our goal at Medichecks is to empower you to do so.

And each one of us needs different nutrients to suit our body, lifestyle, and biology.

Just look at the data from our annual health report, where we analysed 12,992 magnesium blood test results from 1.1.2025-31 to 31-12-2025.

Amazingly, 76% of the results were in the optimal range for magnesium, with levels between 0.85 and 1.0 nmol/L. This could be due to magnesium supplementation, but could also be from people following a balanced diet.

There were around 9% of the results that showed levels of magnesium that were 1.0 nmol/L or over – meaning no supplements were necessary.

And around 15% of the results were suboptimal – below 0.85 nmol/L.

Here’s how to choose the right supplements for your health needs.

Step 1: Determine your nutrient baseline
 

Before you take any supplements, it’s sensible to start with a blood test to figure out where you’re at.

This means you can build your supplement plan with clarity, and insights built on evidence.

Taking supplements ‘just in case’, or because they’re the latest trend might seem harmless. And in most cases, it’s just a waste of money rather than actually harmful.

But just over 9% of Medichecks magnesium results were high, which may indicate over-supplementation or an underlying condition such as chronic kidney failure or a thyroid issue.

Too much magnesium can cause diarrhoea, muscle weakness, headaches, and irregular heartbeat – although you would need to be taking a lot of magnesium (over 400 mg per day).

So, start with a simple blood test.

Step 2: Do your research
 

You’ve got your blood test results, now what?

If you have deficiencies or your levels of a vitamin or mineral are below optimal (we’ve a normal vs. optimal blog that explains exactly what that means), it’s time to act.

Go to the doctors, speak to a pharmacist, or look for supplement guides online to help you decide what you need based on your results.

The NHS have a useful guide for safe doses and guidance on vitamins and minerals.

You’ll want to consider things like:

• Supplement format – do you need gummies for on the go, sprays for simplicity, liquids for faster absorption or good old-fashioned tablets?
• Supplement formulation – which ingredients make your targeted mineral or vitamin most bioavailable?
• Supplement dosage – do you need a high dose to beat a deficiency, or a low dose for a gentle boost?
  Check the RDA % on the package, for example, if you’re getting 100% of your daily vitamin D from one supplement, you don’t want to take a multivitamin that also contains vitamin D.
• Supplement source – always buy from a reputable source and remember sometimes the best formulations come in basic bottles (it’s easy to be drawn in by pretty packaging and clever marketing).

We’ve a few a few useful supplement guides to get you started:

• Magnesium supplement guide
• Vitamin D supplement guide
• Iron supplement guide
• Vitamin supplement guide
• Testosterone supplement guide

Step 3: Create a supplement plan
 

When planning your supplement routine, you should consider timings and whether to take them with or without food.

What supplements should I take with food?

Fat-soluble vitamins such as vitamins A, vitamin D, vitamin E, and vitamin K should be taken with foods that contain healthy fats such as oily fish or avocados, as this will aid absorption.

Taking magnesium and iron supplements with food can help prevent stomach irritation – just avoid foods containing calcium as they can inhibit absorption.

Omega-3 is also best taken with fat-containing foods.

Supplements to avoid taking with food

Water-soluble vitamins such as B vitamins and vitamin C are best taken on an empty stomach for optimal absorption.

And avoid taking iron supplements with any caffeinated food or drinks – this can limit the absorption.

Supplements and drug interactions

If you’re on any medication you should always check with your doctor or pharmacist before starting new supplements, as some supplements can interact with drugs.

Examples include St. John’s Wort, vitamin E, magnesium, and iron.

When is the best time to take my supplements?

Supplements can be taken at any time of day, although some studies suggest this may affect their absorption.

Many find iron is better to take at night as it can cause nausea. Magnesium supplements marketed for sleep should be taken before bedtime.

The best thing is figure out what works for you.

 

Step 4: Start your supplement plan
 

Now it’s the exciting part, starting your new supplement routine. Although, this might feel slightly anti-climactic.

Our annual health survey found that one third of respondents found it difficult to make new habits stick, so let’s look at some tips to maximise your results.

Start small

If you’re starting multiple supplements at once, it’s a good idea to pick one to try first for a month, before introducing any others.

There are a few reasons for this:

1. If you experience any side effects, you’ll know which supplement is causing them
2. You’ll be able to know if your supplements are interacting badly with any other medications you’re taking
3. It will be easy to see how effective the supplement is

Habit stack

Consistency is key with supplement use, but consistency can be hard.

A trick to make things easier is to attach taking supplements to a habit you already consistently do.

Putting on socks, brushing your teeth, checking your phone – if these are things you do at the same time every day, put your pack of supplements (and anything you need to take them with) next to these items and that should remind you to take them.

How long will it take for my supplement to work?

In many cases, the effects of supplements aren’t immediate, but rather a gradual change over time. And it depends on a few things.

Including:

• The severity of your deficiency
• Your dosage
• The quality and formula of your supplement
• Your consistency
• Your overall lifestyle, habits, and underlying conditions

The general consensus is that it takes about a month before you might notice subtle results. Supplements taken for skin, hair, or nails usually show changes in three months.

How long does it take magnesium supplements to work?

Interestingly, if you’re taking magnesium supplements for relaxation, sleep, or anxiety, you may notice a difference in your mood soon after taking them. But studies have shown magnesium supplements take a few months to build up and “correct” a deficiency.

It’s most likely a combination of the placebo effect and self-care ritual that are releasing a feel-good reaction to your magnesium.

Saying it’s a placebo effect is not to say magnesium supplements don’t work. They should help you build up a decent magnesium level again. And the placebo effect is a powerful psychological tool that is not yet fully understood.

Step 5: Track and monitor
 

The levels of vitamins and minerals in our bodies are constantly fluctuating. So, it’s important to keep an eye on your biomarker levels.

Usually, it’s recommended that you test specific biomarker levels again after 12 weeks to see where you’re at. You can do from the comfort of your home with a finger prick test.

Then, a more comprehensive test once a year can help you make sure everything is in order.

Congratulations, you’ve taken control of your health!

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References

1. NHS, Vitamins and minerals. In: nhs.uk [Internet]. [Accessed 17 Dec 2025]