Supplements for memory and concentration

Concentration is the most sensitive thing in the body to sleep debt. Two short nights will do more to your afternoon than any supplement will undo, and the same goes for skipped meals, dehydration and a double espresso at four o'clock.

It is not the answer people searching for a supplement want, but it is the honest order of operations: sleep, food, movement, then nutrients to fill what is left.

DHA is a long-chain omega-3 fat and one of the main structural fats in the brain. In Great Britain it carries an authorised claim — it contributes to the maintenance of normal brain function — at a daily intake of 250mg.

Most UK adults eat well under the recommended two portions of oily fish a week, so this is a real gap rather than a manufactured one. When you read a label, find the DHA figure in milligrams. Many fish oils lead with total omega-3 or EPA, and the DHA line can be surprisingly small.

B12 has two authorised claims relevant here: it contributes to normal psychological function, and to the reduction of tiredness and fatigue. It is found in animal foods and fortified products, and absorption depends on stomach acid.

Acid production tends to fall with age, and some commonly prescribed long-term medicines reduce B12 absorption further. Anyone eating a vegan diet needs a reliable source. If you are persistently exhausted, ask your GP rather than guessing — B12 status is a blood test, not a hunch.

Choline is an essential nutrient the body uses to make acetylcholine, a neurotransmitter involved in memory. Phosphatidylserine is a phospholipid found in nerve-cell membranes. Lion's mane is an edible mushroom. All three are widely sold and none carries an authorised health claim in Great Britain.

That is worth knowing before you pay a premium for them. They may be reasonable inclusions in a formula, and the amounts should still be published — but nobody is permitted to promise you an effect, and honest labels do not try.

It shows that nutrient shortfalls affect how the brain works, that DHA and B12 have been assessed well enough to carry claims, and that diet and sleep have larger effects than most capsules.

It does not show that a supplement will sharpen a well-fed, well-rested brain, and it does not support any claim that a supplement treats, prevents or slows a medical condition. Nothing sold as a food supplement is a treatment, whatever the packaging implies.

Book an appointment if memory changes are getting steadily worse, if they are interfering with everyday tasks, if family have noticed, or if exhaustion is persistent. Thyroid problems, low B12, anaemia, sleep apnoea, depression and medication side effects are all common, all checkable and all treatable.

A supplement is a poor substitute for finding out which of those it is.

Enervia is a once-daily capsule with DHA from cod liver oil, phosphatidylserine, choline, lion's mane, vitamin B12 and astaxanthin, every amount printed on the bottle. Two of those carry authorised claims and four do not — we would rather you knew which was which.

It contains fish, so it is not suitable if you have a fish allergy or follow a vegetarian or vegan diet. Every order has 60 days from delivery for a refund, so you can judge it over a fair stretch with your money still recoverable.