Blog · Ingredient safety
Alpha Lipoic Acid Side Effects: Common, Rare and Worth a Call
Alpha lipoic acid side effects are usually mild: nausea, vomiting, stomach upset and skin rash. The rarer risk is low blood sugar, especially with diabetes medicine, and a few cases of insulin autoimmune syndrome. Synaptril lists ALA second in its 575 mg blend and prints no amount, so its dose per capsule is unknown.
Written by the Synaptril label deskUpdated · 4 min read
Common01
What are the most common alpha lipoic acid side effects?
The most common alpha lipoic acid side effects are nausea, vomiting and indigestion. Some people report a skin rash. These reports come from supplement fact sheets, not from large safety trials (Linus Pauling Institute, Lipoic Acid) (MSKCC, Alpha-Lipoic Acid).
Most studies used doses of 300 to 600 mg a day or more. The stomach complaints tend to show up at higher doses, and they often ease when the dose drops.
The Linus Pauling Institute also notes rare severe allergic reactions after intravenous use, which is a hospital setting and not a capsule matter (Linus Pauling Institute, Lipoic Acid).
If you notice a rash, hives, swelling of the face or trouble breathing, stop the product and seek care at once.
Blood sugar02
Can alpha lipoic acid cause low blood sugar?
Yes, alpha lipoic acid can lower blood sugar, and the effect can add to diabetes medicine. People who take insulin or pills for diabetes should talk to a provider before using it, so glucose checks can be planned (Linus Pauling Institute, Lipoic Acid).
There is also a rare condition called insulin autoimmune syndrome, where the body makes antibodies that swing blood sugar low. About 27 cases tied to ALA have been reported, mostly in Japan, in people with a certain genetic makeup (MSKCC, Alpha-Lipoic Acid).
Signs of low blood sugar include shakiness, sweating, sudden hunger, a pounding heart and confusion. Eat or drink something sugary and call a physician if they appear.
| Effect | How often reported | Action |
|---|---|---|
| Nausea, upset stomach | Most common | Lower the dose, ask a physician |
| Skin rash | Less common | Stop and call a physician |
| Low blood sugar | Rare alone, likelier with diabetes drugs | Plan glucose checks first |
| Insulin autoimmune syndrome | About 27 cases | Seek care at once |
On the label03
How much alpha lipoic acid is in Synaptril?
The Synaptril label does not say how much alpha lipoic acid is in a capsule. It lists ALA second in a 575 mg proprietary blend, so it weighs no more than the glycinate ahead of it.
Label rules cap it at 288 mg, and the magnesium glycinate math suggests under about 175 mg (21 CFR 101.36, supplement labeling). Both are our estimates from the label, not lab results. A tested dose in the small studies was 600 mg, which is well above either figure.
Lower dose does not mean no effect, and it does not mean no risk. It means the research cannot be read straight across to this capsule. See the alpha-lipoic acid page for the full profile.
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See packsWho should ask first04
Who should ask a physician before taking alpha lipoic acid?
Anyone on diabetes medicine, and anyone with a medical condition, should ask a physician before taking alpha lipoic acid. The Synaptril label says the same: consult a physician if you take a medication or have a condition.
Capsules are not for anyone under 18 or pregnant or nursing. Keep taking prescribed medicine, and never change a dose because of a supplement.
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FAQ05
ALA side effect questions
Should alpha lipoic acid be taken with food?
Food lowers absorption, with peak levels about 30% lower, so the Linus Pauling Institute suggests about 30 minutes before a meal (Linus Pauling Institute, Lipoic Acid). The Synaptril label gives no food rule, only one capsule daily.
Do alpha lipoic acid side effects go away?
Mild stomach upset often eases when the dose is lowered or the product is stopped. A rash or low blood sugar signs need a physician's advice. Do not wait for them to pass if they feel severe.
Can alpha lipoic acid interact with thyroid or cancer medicine?
The fact sheets we cite focus on diabetes drugs. Other interactions are less documented, which is a reason to ask, not a sign of safety. Bring the Supplement Facts panel to the pharmacist.
Is the alpha lipoic acid in Synaptril the same as in the studies?
The label does not say whether it is the R-form, the S-form or a mix, and it does not print the amount. The small Alzheimer's studies used 600 mg a day (Linus Pauling Institute, Lipoic Acid), so they do not map onto this capsule.
How soon do alpha lipoic acid side effects start?
Stomach upset can show within hours of a dose. Low blood sugar tends to follow a meal gap. Rashes may take a few days. There is no trial of Synaptril, so we cannot give a timeline for this product.
Who wrote this06
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Read our editorial standards and how we check reviews. This website is run by an American Synaptril authorized shop, not by the manufacturer or the distributor. We earn money when you buy through our order links.
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Ready to try Synaptril?
Start with a medicine check, then choose your pack. Three or six bottles cost less per bottle and ship free, and each pack comes with the 60-day money-back guarantee.
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- 60-day money-back guarantee
- Ships from the U.S.