Vitamin B12 injections have had a lot of attention lately, often promoted as a quick fix for tiredness. The reality is more specific than that — and more useful. For some people, B12 injections are genuinely important. For others, they will do nothing at all. Here is how to tell the difference.
Vitamin B12 is essential for making healthy red blood cells, for keeping your nervous system working properly, and for releasing energy from the food you eat. Your body cannot make it, so it has to come from your diet — mainly from meat, fish, eggs and dairy — or from supplements.
Your body stores B12 in the liver, often enough for a couple of years, which is why deficiency tends to develop slowly and can go unnoticed for a long time.
For most people, diet and, if needed, tablets are enough. Injections matter when the problem is not how much B12 you take in, but whether your body can absorb it.
Absorbing B12 from food is a surprisingly complicated process involving your stomach and the last part of your small intestine. When that process is disrupted, swallowing more B12 does not help — which is why it is given by injection instead, bypassing the gut entirely.
B12 deficiency can cause extreme tiredness, breathlessness, pale skin, a sore or red tongue, mouth ulcers, pins and needles, muscle weakness, problems with balance, memory or concentration difficulties, and low mood.
The nerve-related symptoms matter most. Untreated B12 deficiency can cause nerve damage that may not fully reverse, so pins and needles, numbness or balance problems should never be left to see how they go. Get them checked.
If your B12 levels are normal, there is no good evidence that injections will boost your energy, help you lose weight, strengthen your immune system or make you feel better. Your body simply removes what it does not need. B12 has become a popular wellness purchase, but for someone who is not deficient, the main effect is on their wallet.
There is a second reason to be careful. Tiredness has a long list of possible causes — an underactive thyroid, iron deficiency, poor sleep, diabetes, depression, and many others. Treating yourself with B12 when the real cause is something else means the actual problem goes unfound for longer. A blood test settles it.
If you have symptoms and have never been tested, start with your GP — a simple blood test will show whether B12 or folate is low, and it is usually checked alongside other common causes of tiredness.
If you already know you need B12 and want your injections done locally without waiting for a surgery appointment, we can help. Our vitamin B12 injection service costs £29.99 per injection, given by our pharmacist in a private consultation room, following a short suitability check. If we do not think it is right for you, we will tell you.
Not sure where you stand? Come and talk to our pharmacist. There is no charge for the conversation, and no obligation. Call 01626 854977 or pop into the pharmacy on Old Exeter Street.
Reviewed by: Guo How Chin, Superintendent Pharmacist (GPhC premises reg. 1030793)
Last clinically reviewed: 6 September 2026
Sources: NHS: Vitamin B12 or folate deficiency anaemia · NHS: B vitamins and folic acid
This article is general information and does not replace individual advice from a healthcare professional. If you have symptoms that concern you, please speak to your GP or our pharmacy team.
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