Alpha-lipoïnezuur is een supplement met één bewezen nuttig effect: het verlicht de brandende, stekende en doffe sensaties bij zenuwschade door diabetes. Bij toediening via infuus in een dosis van 600 mg per dag gedurende ongeveer drie weken verminderden de scores voor neuropathiesymptomen met ongeveer een kwart meer dan placebo in vier trials. Een capsule van 600 mg per dag halveerde die symptomen ongeveer na vijf weken in de SYDNEY 2-trial. Bij gebruik als capsule over maanden tot jaren is het effect op de onderliggende zenuwschade kleiner, en een vierjarige trial toonde geen verandering in de belangrijkste zenuwmeting. Gecombineerde trials tonen een klein gewichtsverlies, ongeveer één kilogram meer dan placebo na enkele maanden.
Ze tonen bescheiden verbeteringen van de bloedsuikerspiegel bij mensen met metabole ziekte, al zijn die trials klein en gevarieerd. De brede antioxidatieve en anti-aging beloftes op het etiket berusten grotendeels op cel- en dierstudies. Alpha-lipoïnezuur kan de bloedsuikerspiegel verlagen, dus iedereen die insuline of een sulfonylurea gebruikt moet oppassen voor hypoglykemie. Het kan ook zelden een auto-immuunvorm van lage bloedsuiker uitlokken.
Findings & Outcomes
What It Is
Alpha-lipoic acid is a small sulfur-containing molecule, also labeled thioctic acid, that the body makes in its own mitochondria. There it works as a cofactor, helping the enzyme pyruvate dehydrogenase turn food into energy. The body makes all it needs for that job, and food adds only traces, from organ meats, red meat and some vegetables. So a 600 mg daily supplement is not correcting a shortage; it delivers a drug-sized dose for a different purpose, an antioxidant (redox) effect.
What It Does
By drip at 600 mg a day for about 3 weeks, alpha-lipoic acid lowered the Total Symptom Score roughly 24% more than placebo. That came across four trials of 1,258 people, and the score rates diabetic nerve symptoms.
The oral capsule works too. In the SYDNEY 2 trial, a 600 mg daily dose cut the symptom score about 51% over 5 weeks, against 32% on placebo.
The Research & Studies
Everything here is based on the research we have collected and checked, sorted into groups and ordered with the strongest evidence first. Click any claim to open the studies behind it.
Pain
Oral 600 mg a day cut diabetic nerve symptoms about 51% over 5 weeks (SYDNEY 2)
Taking a 600 mg alpha-lipoic acid capsule daily for five weeks cut the burning, stabbing and numb feeling of diabetic nerve damage roughly in half, clearly more than a dummy pill, and taking more than 600 mg did not add any benefit.
The SYDNEY 2 trial randomized 181 diabetic patients in Russia and Israel to oral alpha-lipoic acid at 600, 1,200 or 1,800 mg a day, or placebo, for 5 weeks after a 1-week placebo run-in. The primary outcome was change in the Total Symptom Score. Mean TSS fell by 4.9 points (51%) at 600 mg, 4.5 (48%) at 1,200 mg and 4.7 (52%) at 1,800 mg, versus 2.9 points (32%) on placebo (all P < 0.05 vs placebo), with responder rates of 62%, 50%, 56% and 26% respectively. Stabbing and burning pain, the Neuropathy Symptoms and Change score, and patients' global assessment of efficacy also favored all three doses; the Neuropathy Impairment Score was only numerically reduced. Higher doses brought a dose-dependent rise in nausea, vomiting and vertigo, so the authors concluded 600 mg once daily gives the best risk-to-benefit ratio.
Who this may not transfer to:Both sexes were enrolled; the trial did not break the symptom results out by sex.
This is the practical at-home form and dose for diabetic nerve symptoms. It relieves the symptom over weeks; it is not shown to repair the nerve, and it sits on top of blood-sugar control, not in place of it. Anyone on insulin or a sulfonylurea should read the hypoglycemia caution before starting.
The study · 1
Ziegler et al., Oral treatment with alpha-lipoic acid improves symptomatic diabetic polyneuropathy: the SYDNEY 2 trial · Diabetes Care 2006;29(11):2365-2370
Intravenous 600 mg a day for 3 weeks lowered nerve symptoms about 24% more than placebo
Adding up four trials, a three-week course of alpha-lipoic acid given by a drip lowered diabetic nerve symptoms about a quarter more than a dummy infusion, with just over half the treated patients clearly responding versus about a third on placebo. This short intravenous course is the most consistent evidence for the supplement.
This meta-analysis searched the manufacturer's (VIATRIS/MEDA) trial database for randomized, double-masked, placebo-controlled, parallel-group trials of 600 mg a day intravenous alpha-lipoic acid for 3 weeks in diabetic polyneuropathy scored by the Total Symptom Score. Four trials (ALADIN I, ALADIN III, SYDNEY, NATHAN II) totaling 1,258 patients (716 on alpha-lipoic acid, 542 on placebo) met the criteria. After 3 weeks the relative difference favoring alpha-lipoic acid was 24.1% for TSS (95% CI 13.5 to 33.4) and 16.0% for the Neuropathy Impairment Score of the lower limbs. Responder rates were 52.7% versus 36.9% (P < 0.05). The improvement grew day by day and became detectable after 8 days.
Who this may not transfer to:Both sexes were included across the pooled trials, which did not report the symptom effect separately by sex.
The intravenous route carries the most consistent signal but is a clinic procedure, not a self-administered option, and the effect is on symptoms over weeks, not on the course of the nerve disease. That the trials all came from a single manufacturer's database is worth weighing.
The study · 1
Ziegler et al., Treatment of symptomatic diabetic polyneuropathy with the antioxidant alpha-lipoic acid: a meta-analysis · Diabet Med 2004;21(2):114-121
Over 4 years, the daily capsule did not change the main nerve measure (NATHAN 1)
Over four years the daily capsule did not beat a dummy pill on its main, objective measure of nerve function, though it did a little better on some secondary scores. So it eases symptoms in the short term but is not shown to slow the underlying nerve damage over years.
The NATHAN 1 trial randomized 460 diabetic patients with mild-to-moderate distal symmetric polyneuropathy to 600 mg a day of oral alpha-lipoic acid (n = 233) or placebo (n = 227) for 4 years. The primary composite endpoint combined the Neuropathy Impairment Score of the lower limbs with seven nerve-conduction and sensory tests, and the change from baseline did not differ between groups (P = 0.105). Change was significantly better with alpha-lipoic acid for the broader Neuropathy Impairment Score (P = 0.028), NIS-LL (P = 0.05) and a muscle-weakness subscore, and more patients showed a clinically meaningful improvement while fewer progressed. Because the placebo group's primary score did not deteriorate significantly, the trial could not demonstrate the secondary prevention it was designed to test. Serious adverse events were higher on alpha-lipoic acid (38.1% vs 28.0%).
Who this may not transfer to:Both sexes were enrolled under the trial's contraception and postmenopausal criteria; results were not reported separately by sex.
This is the limit on the popular claim: relieving symptoms over weeks is not the same as halting nerve damage over years, and on the harder, objective endpoint the daily capsule did not separate from placebo. Read it alongside the short-term symptom benefit, not instead of it.
The study · 1
Ziegler et al., Efficacy and safety of antioxidant treatment with alpha-lipoic acid over 4 years in diabetic polyneuropathy: the NATHAN 1 trial · Diabetes Care 2011;34(9):2054-2060
Weight And Fat Loss
About 1.3 kg more weight loss than placebo over a few months
Adding up the trials, people taking alpha-lipoic acid lost about 1.3 kg more than those on a dummy pill over a few months, a real but small difference. It is not a weight-loss drug, and it works best as a minor add-on to diet and activity.
This meta-analysis identified 10 randomized, double-blind, placebo-controlled studies (11 eligible studies, 12 treatment arms; 534 people on alpha-lipoic acid, 413 on placebo) across populations with diabetes, metabolic syndrome, rheumatoid arthritis, non-alcoholic fatty liver disease and dedicated weight-loss cohorts. Alpha-lipoic acid was associated with 1.27 kg greater weight loss (95% CI 0.25 to 2.29) and a 0.43 kg/m2 lower BMI (95% CI 0.03 to 0.82) than placebo. Doses spanned 300 to 1,800 mg a day and durations 8 to 52 weeks; meta-regression found no significant effect of dose, and study duration affected the BMI change but not the weight change. The authors describe the effect as small, short-term and in need of longer trials.
Who this may not transfer to:Trials enrolled both sexes across varied conditions; the pooled analysis did not report the weight effect separately by sex.
Expect little. A kilogram over a few months is a minor add-on, not a reason to expect meaningful weight loss on its own, and the trials were short. Put the effort into the diet, movement and sleep that move weight further.
The study · 1
Kucukgoncu et al., Alpha-lipoic acid (ALA) as a supplementation for weight loss: results from a meta-analysis of randomized controlled trials · Obes Rev 2017;18(5):594-601
How it works
A mitochondrial energy cofactor that also acts as a redox antioxidant
Your body makes alpha-lipoic acid to help its cells produce energy. The supplement doses add a second job: acting as an antioxidant that recharges vitamins C and E and boosts the cell's own antioxidant, glutathione. Most of that antioxidant story is shown in cells and animals, not in people.
Alpha-lipoic acid (1,2-dithiolane-3-pentanoic acid) is made in the mitochondrion from octanoic acid and, in its protein-bound R form, is a required cofactor for mitochondrial alpha-ketoacid dehydrogenases including pyruvate dehydrogenase, placing it at the center of energy metabolism. Oral supplements deliver mostly unbound alpha-lipoic acid, which is absorbed variably (roughly 20 to 40% of a dose), accumulates transiently in liver, heart and skeletal muscle, and is rapidly metabolized and excreted. As a redox couple with dihydrolipoic acid it scavenges reactive species, regenerates the oxidized forms of vitamins C and E, restores glutathione, chelates metals, and has been shown to activate Nrf2-driven detoxification and repress NF-kappa-B signaling in laboratory systems. The one condition where these properties have translated into defined human benefit is diabetic polyneuropathy; the broader anti-aging and vascular claims rest largely on preclinical work.
The study · 1
Shay et al., Alpha-lipoic acid as a dietary supplement: molecular mechanisms and therapeutic potential · Biochim Biophys Acta 2009;1790(10):1149-1160
Blood Sugar
Modest improvements in fasting glucose and HbA1c, from small varied trials
Adding up 24 trials in people with diabetes or metabolic problems, alpha-lipoic acid improved fasting blood sugar and HbA1c somewhat, but the trials were small and varied a lot, so this is a modest and uncertain effect, not a substitute for diabetes treatment.
This systematic review and meta-analysis pooled 24 randomized controlled trials of alpha-lipoic acid in patients with metabolic diseases (type 2 diabetes, metabolic syndrome and related conditions). Reported as standardized mean differences, alpha-lipoic acid significantly reduced fasting glucose (SMD -0.54; 95% CI -0.89 to -0.19; P = 0.003), insulin (SMD -1.01), HOMA-IR (SMD -0.76), HbA1c (SMD -1.22; 95% CI -2.01 to -0.44), triglycerides, total cholesterol and LDL cholesterol, with no effect on HDL. The confidence intervals are wide and heterogeneity between studies was high, and the individual trials were small, so the size of the real-world effect is uncertain. Alpha-lipoic acid is not established as a standalone glucose-lowering therapy.
Who this may not transfer to:The pooled trials enrolled both sexes and did not report glycemic effects separately by sex.
Treat this as a minor, uncertain add-on, not a diabetes treatment. The more clinically relevant fact is the flip side: because it can lower glucose, combining it with insulin or a sulfonylurea can cause hypoglycemia, so monitoring matters when starting.
The study · 1
Akbari et al., The effects of alpha-lipoic acid supplementation on glucose control and lipid profiles among patients with metabolic diseases: a systematic review and meta-analysis of randomized controlled trials · Metabolism 2018;87:56-69
The Nerve-Pain Evidence
In the drip trials, patients divided cleanly into those who responded and those who did not. Just over half of the treated patients counted as responders, against about a third on placebo. On the 600 mg infusions, the treated patients started to pull ahead of the placebo group after about 8 days.
NATHAN 1 gave a daily 600 mg capsule for 4 years, and its main result, a combined measure of nerve function, was no better than placebo. Some secondary impairment scores improved, and fewer people worsened. It eases symptoms; it is not shown to reverse the damage.
One caveat colors all of this evidence: the four-trial meta-analysis and much of the surrounding evidence trace to a single manufacturer's database, a conflict of interest.
Responders outnumbered non-responders roughly two to one once the drip was under way.
How It Works
The mechanism is redox chemistry. A 600 mg dose briefly puts free alpha-lipoic acid into circulation. There it trades electrons, and loosely binds metals, to blunt the oxidative stress that high blood sugar drives in the nerves.
Anatomy of the Practice
1As a cell's own energy cofactor
The body synthesizes alpha-lipoic acid in the mitochondria, where it is bound to pyruvate dehydrogenase and related enzymes that convert food into usable energy. This role is fully covered by what the body makes.
2As a circulating antioxidant, at supplement doses
A 600 mg oral dose puts unbound alpha-lipoic acid into the blood briefly. There, alpha-lipoic acid and the form it turns into after reacting, dihydrolipoic acid, work as a pair. Together they mop up free radicals, recharge used-up vitamins C and E, and help restore glutathione. Most of this is shown in laboratory and animal studies, and the effects appear at low concentrations.
3In the diabetic nerve
High blood sugar raises oxidative stress in peripheral nerves, and this is the setting where alpha-lipoic acid has been tested most and helped most. Lowering that stress is the proposed route to easing the burning and tingling.
Ways to Do It
For most people this is a single decision: a 600 mg daily capsule, taken for diabetic nerve symptoms. The other uses are smaller, and the food route matters less here than for most supplements.
Red meat, organ meats and some vegetables carry small amounts of alpha-lipoic acid, and your body makes the rest. Much of the type 2 diabetes this is used for tracks back to diet: ultra-processed foods supply roughly 57% of the calories in the average US adult diet. For the disease itself, blood-sugar control, weight, activity and foot care do the work; alpha-lipoic acid adds to them.
This is the dose and form behind the SYDNEY 2 at-home evidence: 600 mg once daily. Take it on an empty stomach, since food lowers how much is absorbed. If you take insulin or a sulfonylurea, read the cautions first.
The most consistent trial signal used 600 mg a day by infusion for about three weeks. It is a clinic procedure administered by a clinician, and it suits someone with troublesome diabetic nerve symptoms who wants the best-evidenced version.
Pooled trials put the weight effect near a kilogram and the blood-sugar effect at modest, from small and varied studies. If you try it for these, treat it as a minor add-on to diet, movement and medication.
Most trials used the racemic (R/S) mix. The R form is the one the body uses, and dedicated evidence for R-only products is limited. The molecule degrades with heat and moisture, so keep capsules cool and dry, and replace an old bottle.
Go Deeper
Away from the nerves, the effects are small: pooled trials put weight loss at about 1.27 kg more than placebo, with a small drop in BMI. A separate meta-analysis in diabetes or metabolic syndrome found only modest improvements, small drops in fasting glucose and HbA1c, from small, uneven trials. None of that makes it a diabetes treatment on its own.
For blood sugar in type 2 diabetes, the 600 mg capsule sits with other options, behind the diet and movement that do the real work:
- Blood sugar: the metabolic target these trials measured.
- Berberine: a plant alkaloid studied for the same goal.
- Magnesium: a mineral with its own blood-sugar evidence.
- Type 2 diabetes: the condition these uses sit under.
The label's broader antioxidant and anti-aging promises are the weakest claim. Unlike the 1,258-patient nerve program, no human trial has tested them for aging, memory, cognition or lifespan; the support stays in cell and animal work. Since no study has looked for a benefit there, none has turned up. That leaves the anti-aging claim untested, and the human evidence simply absent.
Cautions For This Practice
Extra restraintEverything to be aware of is here, in one place. This practice suits most healthy people; a few situations call for real care.
Higher oral doses (1,200 to 1,800 mg) cause dose-related nausea without added benefit
SYDNEY 2 compared oral alpha-lipoic acid at 600, 1,200 and 1,800 mg a day against placebo for 5 weeks in 181 people with symptomatic diabetic polyneuropathy. Symptom improvement was essentially the same across the three active doses (51%, 48% and 52% Total Symptom Score reductions), but the safety analysis showed a dose-dependent rise in nausea, vomiting and vertigo as the dose increased. On this basis the trial identified 600 mg once daily as the dose with the optimum risk-to-benefit ratio, which is why later trials and practice settled on it.Ziegler et al., Oral treatment with alpha-lipoic acid improves symptomatic diabetic polyneuropathy: the SYDNEY 2 trial
Can rarely trigger insulin autoimmune syndrome (autoimmune low blood sugar)
Insulin autoimmune syndrome, or Hirata disease, is a rare cause of autoimmune hypoglycemia marked by high measured insulin and anti-insulin autoantibodies, first described in Japan in 1970. It is typically triggered by sulfhydryl-containing drugs, which stimulate insulin autoantibody production, and alpha-lipoic acid (a sulfhydryl compound) has emerged as a cause since the first reports from Japan around 2006. Two case reports from an Italian center document the temporal link, with hypoglycemia resolving after the supplement was stopped. Susceptibility is associated with specific HLA class II types (HLA-DRB1*04:06 reported more in East Asian patients and HLA-DRB1*04:03 in patients of European descent), which is why cases have been concentrated in, but are not limited to, East Asian populations.Moffa et al., Potential cause-effect relationship between insulin autoimmune syndrome and alpha lipoic acid: two case reports
Low blood sugar, especially with insulin or a sulfonylurea
Alpha-lipoic acid can lower blood glucose. On top of insulin or a sulfonylurea (glipizide, glimepiride, gliclazide and the like) that can add up to hypoglycemia. If you take a glucose-lowering medication, monitor your blood sugar more closely at first. Have your prescriber check whether the dose needs adjusting. The symptoms to know are shakiness, sweating, confusion and a racing heart.
A rare autoimmune form of low blood sugar
Rarely, alpha-lipoic acid triggers insulin autoimmune syndrome, also called Hirata disease. The immune system makes antibodies against insulin, causing episodes of severe low blood sugar unrelated to any diabetes medication. It is linked to certain immune-gene (HLA) types and has been reported more in East Asian populations, though cases occur in people of European descent too. It is uncommon, but recurrent unexplained hypoglycemia in someone taking the supplement is a reason to stop it and get checked.
Nausea and stomach upset at higher doses
At 600 mg a day alpha-lipoic acid is generally well tolerated. In the trials, 1,200 and 1,800 mg a day raised nausea, vomiting and dizziness without adding benefit. 600 mg is the dose that has been used. Taken on an empty stomach it can be harder on the stomach for some people.
Pregnancy, breastfeeding and children
There is little trial data in pregnancy, breastfeeding or childhood, so there is no established safe dose in these groups. Avoid it in these groups without a specific medical reason.
If you are unwell or on several medications, talk it through first
If you have diabetes on several drugs, or thyroid, kidney or liver disease, raise alpha-lipoic acid with your prescriber first, so the blood-sugar interaction is weighed against your situation.
Start slow, be smart, read the research, and consult a professional if you have any concerns. This is here to inform your choice, not make it for you.
Common Questions
Can I take alpha-lipoic acid with metformin?
Metformin on its own rarely causes low blood sugar, so the hypoglycemia risk from adding alpha-lipoic acid is smaller than with insulin or a sulfonylurea. It is still sensible to check your blood sugar when you start, and to tell whoever manages your diabetes.
Is it safe to take for years?
Long-term safety data is thin outside one large trial, so year-on-year use is best reviewed with your prescriber. A 600 mg daily capsule was generally well tolerated across the 4-year NATHAN 1 trial.
Explore Related
Other pages this one connects to, by the evidence they share, the outcomes they touch, and the ground they cover.
All 8 sources on this page independently checked and cross-referenced.
Thomas Dehli, Founder & Editor, Sacred Lotus
Sacred Lotus has published Chinese medicine reference material since 2001. Integrative pages are held to the same standard as the herb and formula library: cite the source, grade the claim at its real strength, and say where the research has not looked. This page is educational and it is not medical advice. Last reviewed and updated August 16, 2026.
Evidence strength
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