Every other day, as directed. The doses are pre-measured, so there is nothing to draw up or calculate.

One pen is sized for a 28-day plan on the standard schedule.

The 750mg is designed for everyday maintenance, for first-time users, and for anyone who wants reliable support without stepping up to high strength.

The 1000mg is the higher-strength option. Most people start on the 750mg.

Seven ingredients. NAD⁺ is the active. The other six are sterile water, sodium chloride, phosphate buffer, benzyl alcohol, magnesium chloride and ascorbic acid, and they exist to keep the NAD⁺ stable, sterile and absorbable.

Every one of them is listed above with what it does.

NAD⁺ is a coenzyme your body already makes and uses in every cell. What is in the pen is pharmaceutical-grade NAD⁺ and water for injection, made in the United Kingdom, with nothing else added. Doses are measured at the factory rather than by you.

It is still an injectable. If you have a diagnosed medical condition, take prescription medication, or are unsure whether it is right for you, speak to your GP or pharmacist before you start.

It is a subcutaneous injection, which means it goes into the fat layer just under the skin rather than into muscle or a vein, using a short fine needle. The pen is pre-loaded, so there is nothing to draw up or measure.

The injection itself is over in a few seconds. Sensation varies from person to person. If one site feels sore, use a different one next time.

Do not use it if you are pregnant or breastfeeding, or if you are under 18.

Speak to your GP or pharmacist first if you take prescription medication, have a diagnosed medical condition, or have reacted badly to an injectable before. If you are not sure, ask before you start rather than after.

The most common are at the injection site: brief redness, mild swelling or tenderness, which usually settles by itself. Rotating where you inject helps.

If you experience any adverse reaction or discomfort, stop using it and consult your healthcare provider.

Yes, at any time from your account. There is no minimum term and no cancellation step to negotiate.

You can also skip a delivery if you are away or still have a pen in the fridge.

Free UK delivery, with a UK-based team if you need to reach someone.

On a plan, your next pen arrives before the last one runs out, so the every-other-day routine never has a gap in it.