People shopping for energy supplements usually look at B vitamins, iron, magnesium and caffeine products such as pre-workouts and energy shots. We explain what each contains and what it can and can't be said to do. If you're tired all the time, sleep, food and a check-up with your GP come before supplements.
All vitamins & supplements · B vitamins & B12 · Iron · Magnesium · Multivitamins · Energy & focus
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Why am I always tired?
Common causes include poor sleep, an unhealthy lifestyle, stress, hormonal changes and some illnesses, according to the NHS. See a GP if you've been feeling tired for a few weeks and you're not sure why, or if it affects your daily life; the NHS advises not to self-diagnose.
The NHS's self-help tips include eating regular meals and healthy snacks every 3 to 4 hours, regular exercise, keeping to regular sleep times, cutting down on caffeine and alcohol, and drinking enough water.
Which vitamins and minerals have tiredness claims?
Several nutrients have an authorised claim to contribute to the reduction of tiredness and fatigue, including iron, magnesium, riboflavin (vitamin B2), niacin (B3), pantothenic acid (B5) and folate. For example, "Iron contributes to the reduction of tiredness and fatigue" and "Magnesium contributes to a reduction of tiredness and fatigue", and the GB register of authorised health claims allows these only for products that are at least a source of the nutrient.
These claims don't mean more is better if you already get enough. Women aged 19 to 49 need 14.8mg of iron a day, and the NHS says high doses (over 20mg) can cause side effects such as constipation and feeling sick; keep iron supplements away from children. Browse B vitamins, iron or magnesium.
Do caffeine and energy products give you energy?
Caffeine has no authorised health claims, so we don't claim energy drinks, shots or pre-workouts reduce tiredness. EFSA says single doses of caffeine up to 200mg, and up to 400mg a day, raise no safety concerns for healthy adults, and up to 200mg a day in pregnancy. Count every source, including coffee, tea and energy drinks.
The NHS notes that caffeine can disrupt sleep, which can leave you more tired, and suggests cutting down gradually. Browse energy and focus products.
We sell the products on this page. That's our commercial interest, and it's why we show the evidence alongside them. This page is general information for adults, not personalised medical advice. Food supplements should not replace a varied, balanced diet.
Written by Andy Arshad, SupplementHQ. Last reviewed 11 October 2026.