Vitamin injections: when they help and when they are just expensive urine
Some of these have a real clinical case. Others are a supplement you could buy for a fraction of the price. It is worth knowing which is which.
Vitamin injections occupy an uncomfortable space between genuine clinical treatment and wellness retail. Some have a solid rationale. Others are the injectable version of something available for a few pounds at a pharmacy.
We offer them, and we would rather tell you honestly which is which.
The general principle
Injection makes sense when one of two things is true:
- Absorption is the problem. If you cannot absorb something through the gut, bypassing it is the point.
- A rapid correction of a documented deficiency is needed. Injection raises levels faster than oral.
If neither applies — you absorb normally and you are not deficient — an injection generally delivers a well-supplied body more of something it already has enough of. Water-soluble vitamins in excess are excreted.
Vitamin B12 — £40
The one with the strongest case. B12 injection is genuine, evidence-based medical treatment for B12 deficiency, and it is the standard of care for pernicious anaemia, where the gut physically cannot absorb it.
Worth having if you:
- Have a documented B12 deficiency.
- Follow a vegan or strictly plant-based diet — B12 occurs almost exclusively in animal products.
- Have had gastric or bowel surgery affecting absorption.
- Have coeliac or Crohn's disease.
- Take metformin or long-term proton pump inhibitors, both of which reduce absorption.
Less worth having if you eat a normal mixed diet, absorb normally and have not tested low. If you are genuinely deficient, your GP can usually provide B12 on the NHS.
Vitamin D — £50
A reasonable case, particularly in the UK. Deficiency is genuinely widespread here — between October and March, UK sunlight is too weak at this latitude for the skin to produce meaningful vitamin D at all.
Worth having if you have tested low, have darker skin (which needs considerably more UV exposure to produce the same amount), cover up for cultural or medical reasons, spend most daylight hours indoors, or have a condition affecting fat absorption.
Honest caveat: for most people, oral vitamin D works perfectly well, is absorbed reliably, and costs a few pounds for months of supply. The injection makes sense for absorption problems or a documented significant deficiency needing rapid correction.
Biotin — £50
The weakest case of the four, and the most marketed. Biotin is prominently sold for hair and nails, and the evidence is genuinely thin.
Biotin deficiency does cause hair loss and brittle nails — but true biotin deficiency is rare. It occurs in specific circumstances: certain genetic conditions, long-term anticonvulsant use, or a diet extraordinarily high in raw egg white.
For someone with normal biotin levels, supplementation has not been shown to improve hair or nail growth. If your hair is thinning, the investigation of causes — ferritin, thyroid, vitamin D — is far more likely to find the answer.
Vitamin C — £40
Vitamin C is genuinely essential — required for collagen synthesis, immune function and iron absorption. Deficiency causes scurvy.
The honest position: in a country where vitamin C is abundant in ordinary food, actual deficiency is rare. Oral absorption is efficient at normal doses. High-dose intravenous vitamin C is studied in specific clinical contexts, but that is a different intervention in a different setting from an intramuscular injection in an aesthetics clinic.
Reasonable as part of a wellness routine if you enjoy it and understand what you are buying. Not something we would suggest as a treatment for a specific problem.
Glutathione — £100
Covered separately, because it needs a longer and more careful answer. See our piece on glutathione.
Summary
| Price | Case for it | Test first? | |
|---|---|---|---|
| Vitamin B12 | £40 | Strong where deficiency or absorption issues exist | Yes |
| Vitamin D | £50 | Reasonable, especially October to March in the UK | Yes |
| Vitamin C | £40 | Weak — oral works well and deficiency is rare | Not usually needed |
| Biotin | £50 | Weak — deficiency is rare and supplementation is unproven | Yes, and check hair causes |
| Glutathione | £100 | See the dedicated article | Discuss at consultation |
What we would say at a consultation
If you are tired, losing hair, or generally not right, the most valuable thing is a blood test — not an injection chosen from a menu. A treatable deficiency found and corrected is a far better outcome than a course of injections given hopefully.
If you have tested, know what you are low in, and want it corrected quickly, injections are a sensible, safe and quick way to do it.
Common questions
Do vitamin injections actually work?
They work when absorption is impaired or a documented deficiency needs rapid correction. If you absorb normally and are not deficient, water-soluble vitamins given in excess are largely excreted.
Should I have a blood test before vitamin injections?
Yes, for B12, vitamin D and biotin especially. Knowing whether you are actually deficient turns a guess into a treatment, and a treatable deficiency found is a better outcome than injections given hopefully.
Do biotin injections help hair growth?
Only if you are genuinely biotin deficient, which is rare. For normal biotin levels there is no good evidence that supplementation improves hair or nail growth. Investigating ferritin, thyroid and vitamin D is far more likely to find the cause.
Does biotin affect blood tests?
Yes. Biotin supplementation interferes with several common laboratory tests including thyroid function and troponin, and can produce seriously misleading results. Always tell your doctor or phlebotomist that you take it.
Is a vitamin D injection better than tablets?
For most people, oral vitamin D works well and costs a fraction of the price. Injection makes sense where absorption is impaired or a significant documented deficiency needs correcting quickly.
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