Ingredient profile
Alpha Lipoic Acid for Memory: Small Studies, Smaller Dose
Alpha lipoic acid is an antioxidant the body makes in small amounts. Alpha lipoic acid for memory rests on a few small studies at 600 mg a day, and a Cochrane review found no qualifying trials at all. In Synaptril it is second of six in the 575 mg blend, so it likely holds well under 175 mg.
Written by the Synaptril label deskUpdated
The basics01
What is alpha lipoic acid?
Alpha lipoic acid, or ALA, is a sulfur-containing antioxidant that the body makes on its own. Supplements sell it in much larger amounts.
Most human research on ALA is about diabetes and the nerve damage it can cause. Those studies used about 300 to 1,800 mg a day by mouth (Linus Pauling Institute, Lipoic acid).
On the Synaptril label it is named simply "Alpha Lipoic Acid", second in the blend. The form and amount are not given.
| Name on the label | Alpha Lipoic Acid |
|---|---|
| What it is | Antioxidant made in the body |
| Place on the label | 2 of 6 in the 575 mg proprietary blend |
| Amount per capsule | Not listed; #2 of 6 in the 575 mg blend, so at most 288 mg, and likely under 175 mg |
| Amount used in research | 600 mg a day in small dementia studies |
| Strength of evidence | No controlled trials for memory |
| Marketed or traditional use | Antioxidant; studied for nerve pain in diabetes |
| Main caution | May lower blood sugar; rare autoimmune low blood sugar in people with certain genes. |
The evidence02
What does research say about alpha lipoic acid for memory?
Research on alpha lipoic acid for memory is thin. The Linus Pauling Institute says the evidence is too limited to draw conclusions (Linus Pauling Institute, Lipoic acid).
The best-known study gave 600 mg a day to 9 people with Alzheimer's disease who were already on standard drugs. Scores seemed to hold steady for a year, but there was no control group (Linus Pauling Institute, Lipoic acid). A larger trial of 39 patients tested fish oil plus 600 mg of ALA, so the effect of ALA alone cannot be pulled out.
Memorial Sloan Kettering adds that there is no evidence ALA alone benefits thinking. An Alzheimer's trial of ALA with other antioxidants found no protective effect (MSKCC, Alpha-lipoic acid).
| Study | People | Daily ALA | Result |
|---|---|---|---|
| Open study, no placebo | 9 with Alzheimer's | 600 mg | Scores seemed stable for a year |
| Randomized trial, with fish oil | 39 with Alzheimer's | 600 mg | No worsening over 12 months; ALA not tested alone |
| Trial, 10 weeks | People with HIV-related thinking problems | 1,200 mg | No benefit |
| Synaptril capsule | Not tested | Not published | No trial of the product |
Cochrane03
Why is there no Cochrane verdict on ALA for dementia?
There is no verdict because there were no trials to judge. The Cochrane team searched for double-blind, placebo-controlled trials of ALA in dementia and found none that qualified (Cochrane, Alpha-lipoic acid dementia).
Cochrane reviews count only well-controlled trials. An empty review means the question has not yet been tested that way.
ALA cannot be recommended for people with dementia until trial data are available (Cochrane, Alpha-lipoic acid dementia). That is a statement about missing evidence, not proof of harm.
The amount04
How much alpha lipoic acid is in Synaptril?
The label does not say. As second of six in a 575 mg blend, ALA can weigh at most 288 mg, and most likely under 175 mg.
The second number comes from the magnesium line. The magnesium glycinate that supplies 80 mg of magnesium takes at least 400 mg of the blend in a generous case, and about 570 mg if it is pure (Magnesium glycinate, Mg content). ALA shares what is left with four other ingredients.
The studies above used 600 mg a day. The bars show the gap.
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See packsSafety05
Who should be careful with alpha lipoic acid?
People taking insulin or diabetes pills should be most careful, because ALA may lower blood sugar. A few other groups should ask first too.
The Linus Pauling Institute says people on diabetes drugs should watch their glucose closely (Linus Pauling Institute, Lipoic acid). MSKCC adds that ALA may add to the effect of those drugs (MSKCC, Alpha-lipoic acid).
Blood sugar
ALA may push glucose lower when combined with insulin or oral diabetes drugs (Linus Pauling Institute, Lipoic acid).
Insulin autoimmune syndrome
In people with certain HLA-DRB1 genes, ALA has triggered repeated low blood sugar. One woman developed it after 600 mg a day (Okuroglu 2020, ALA and IAS).
Chemo and radiation
As an antioxidant, ALA may interfere with these treatments (MSKCC, Alpha-lipoic acid).
Pregnancy and nursing
The Synaptril label rules them out. LPI also discourages ALA while breastfeeding (Linus Pauling Institute, Lipoic acid).
Do not stop or change a diabetes medicine because you started a supplement. Tell your doctor before you begin so your glucose can be watched. Read more on supplements and medicines.
Side effects06
What side effects can alpha lipoic acid cause?
The most common side effects of ALA are mild: rash, itching, stomach pain, nausea and dizziness. Serious effects are rare at normal doses.
In studies, up to 1,800 mg a day for 6 months and 1,200 mg a day for 2 years were not linked to serious harm (Linus Pauling Institute, Lipoic acid). Synaptril holds far less than that.
- Skin rash and itching
- Stomach pain, nausea, vomiting or diarrhea
- Vertigo
- Low blood sugar, mainly with diabetes drugs (MSKCC, Alpha-lipoic acid)
Keep the bottle away from children. MSKCC notes that children who swallowed ALA by accident have had convulsions (MSKCC, Alpha-lipoic acid). See all Synaptril side effects.
Other ingredients07
Where does ALA fit among the Synaptril ingredients?
ALA is the second ingredient by weight, right after magnesium glycinate. It is the only one of the six with a dementia study at 600 mg.
Compare all seven label lines on the Synaptril ingredients page.
FAQ08
Alpha lipoic acid: questions people ask
What does alpha lipoic acid do for the brain?
No one has shown that it does much. ALA is an antioxidant, and that is the reason it is studied for the brain. MSKCC reports no evidence that ALA alone benefits thinking, and a trial of ALA with other antioxidants found no protective effect in Alzheimer's disease (MSKCC, Alpha-lipoic acid).
Is there human research on alpha lipoic acid and memory?
Yes, but very little. One open study followed 9 Alzheimer's patients on 600 mg a day, and a trial of 39 patients combined ALA with fish oil (Linus Pauling Institute, Lipoic acid). Neither can show that ALA alone helps. The Linus Pauling Institute calls the evidence too limited.
What did the Cochrane review on alpha lipoic acid find?
It found no trials that met its standards, so it had no data to judge (Cochrane, Alpha-lipoic acid dementia). The authors said ALA cannot be recommended for dementia until proper trials exist. That means the question is open, not that ALA was shown to fail.
How much alpha lipoic acid did dementia studies use?
They used 600 mg a day, usually alongside standard Alzheimer's drugs or fish oil (Linus Pauling Institute, Lipoic acid). A trial for HIV-related thinking problems used 1,200 mg and found no benefit. Synaptril's share is unpublished but almost certainly under 175 mg.
Can alpha lipoic acid cause insulin autoimmune syndrome?
Rarely, yes, in people with certain genes. A 2020 report describes a 62-year-old woman who had repeated low blood sugar after taking 600 mg a day; she carried HLA-DRB1*04:03 (Okuroglu 2020, ALA and IAS). Episodes usually fade after stopping, though it can take months.
Is alpha lipoic acid safe while breastfeeding?
Its safety is not established, so the Linus Pauling Institute discourages use while breastfeeding (Linus Pauling Institute, Lipoic acid). The Synaptril label goes further: it is not for pregnant or nursing mothers, or anyone under 18. Ask your doctor about any supplement during this time.
Can alpha lipoic acid interfere with cancer treatment?
It may. MSKCC says ALA's antioxidant action could interfere with chemotherapy and radiation (MSKCC, Alpha-lipoic acid). If you are in cancer care, tell your oncology team about every supplement, including a one-a-day capsule like Synaptril, before you take it.
Who wrote this09
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . See our editorial standards and how we check reviews. This website is run by Getsynaptril, a stocked U.S. Synaptril counter, not by the manufacturer or the distributor. We are paid when you buy through our order links.
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