Alpha-lipoic acid supplements and nerve pain

Alpha-lipoic acid, often shortened to ALA, is a compound the body makes in small amounts and which is involved in energy production in cells. It acts as an antioxidant. It also occurs in some foods and is sold as a capsule or tablet, frequently marketed for nerve health, blood sugar control and general wellbeing. It is not the same as the omega-3 fat alpha-linolenic acid, which shares the abbreviation.

Its popularity in nerve pain follows from a theory that high blood sugar produces oxidative stress that damages nerves, so an antioxidant might protect them. Whether this works in people has been tested in a number of trials.

NCCIH describes the evidence as mixed. One 2022 review looked at 8 studies with 1,500 participants and found inconsistent results: three studies reported improvements in symptoms and five did not. Another 2022 review of 9 studies with 2,062 participants suggested alpha-lipoic acid might help reduce pain in people with diabetic neuropathy.

The reviews came to different conclusions partly because the trials differed in dose, length, how pain was measured and how people were chosen. The honest summary is that a modest benefit is possible but unproven, and that it has not replaced standard care. The NCCIH pages used for this guide do not give an agreed effective dose, so a figure should not be taken from a product label as proof of benefit.

NCCIH cites a 2020 review of 71 studies including 4,749 people that judged ALA supplementation to be safe across healthy people and a range of patient groups, including people with diabetes. The common side effects described were mild: headache, heartburn, nausea and vomiting.

Safety in a trial setting does not cover every situation. Long-term use, high doses and use in pregnancy, breastfeeding and childhood are not well covered by the NCCIH pages used for this guide, so a pharmacist or doctor should be asked. Because ALA could in principle lower blood sugar, people on insulin or tablets for diabetes should discuss it with their diabetes team so that glucose monitoring can be adjusted if needed.

The NHS peripheral neuropathy page puts the main weight on treating the underlying cause. For diabetes that means managing blood sugar and lifestyle factors such as stopping smoking, cutting alcohol, weight management and exercise. Vitamin B12 deficiency is treated with injections or tablets, and neuropathy caused by a medicine may improve when the medicine is stopped.

For the pain itself, the NHS says ordinary painkillers such as paracetamol and ibuprofen are typically not effective for nerve pain. Medicines it lists are amitriptyline, duloxetine, pregabalin and gabapentin, started at low doses and gradually increased, with tiredness and dizziness among the common side effects. Capsaicin cream or patches can help localised pain, and tramadol is an option when other treatments fail.

The page also notes that some people find complementary approaches such as acupuncture, herbal medicine, benfotiamine and alpha-lipoic acid helpful, but that the evidence is not always clear, and it recommends talking to a doctor before trying them.

Treat it as an add-on rather than a replacement. Do not stop or reduce prescribed nerve-pain medicines or diabetes treatment because a supplement seems to help.

Keep a simple symptom diary so you can judge whether anything has changed. Choose one product at a time from a reputable pharmacy or retailer, and bring the label to your appointment.

• Tell your GP, diabetes nurse or pharmacist you are taking it.

• Check blood glucose as your team advises, in case your readings change.

• Stop and seek advice if you develop rash, swelling or persistent vomiting.

• Avoid products that promise to cure neuropathy.

Numbness, tingling or burning in the feet or hands that is new, spreading or worsening should be assessed by a GP, because the cause matters. People with diabetes should have regular foot checks, and any foot sore, blister, colour change or loss of feeling needs prompt review. Sudden weakness, difficulty walking or loss of bladder or bowel control is an emergency: use NHS 111 or 999.