Jwarrior77
Senior Member
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Apparently R lipoic acid is more bioavailable than alpha Lipoic Acid. Has anyone tried both to see if it has a noticeable difference? Thanks.
There is some evidence that L-ALA may be harmful.
All clinical trials showing benefit from lipoic acid were with regular lipoic acid. Since it contains also half of R-ALA, and the price of R-ALA isn't even by far half that of usual, I've using regular only. Couldn't afford otherwise.
Would you be so kind to provide links?
Overall, the evidence for harmful effects of S-ALA is rather weak, though.
Hope this helps.
Supplements
Unlike lipoic acid in foods, lipoic acid in supplements is not bound to protein. Moreover, the amounts of lipoic acid available in dietary supplements (50-600 mg) are likely as much as 1,000 times greater than the amounts that could be obtained from the diet. In Germany, lipoic acid is approved for the treatment of diabetic neuropathies and is available by prescription (108). Lipoic acid is available as a dietary supplement without a prescription in the US. Most lipoic acid supplements contain a racemic mixture of R-lipoic acid and S-lipoic acid (sometimes noted d,l-lipoic acid). Supplements that claim to contain only R-lipoic acid are usually more expensive, and information regarding their purity is not publicly available (109). Since taking lipoic acid with a meal decreases its bioavailability, it is generally recommended that lipoic acid be taken 30 min prior to a meal (see also Metabolism and Bioavailability) (8).
Racemic mixture versus R-lipoic acid only
R-lipoic acid is the isomer that is synthesized by plants and animals and functions as a cofactor for mitochondrial enzymes in its protein-bound form (see Biological Activities). Direct comparisons of the bioavailability of the oral racemic mixture and R-lipoic acid supplements have not been published. Following the ingestion of R,S-lipoic acid, peak plasma concentrations of R-lipoic acid were found to be 40%-50% higher than S-lipoic acid, suggesting better absorption of R-lipoic acid. Both isomers were nonetheless rapidly metabolized and eliminated (6, 8, 11). In rats, R-lipoic acid was more effective than S-lipoic acid in enhancing insulin-stimulated glucose transport and metabolism in skeletal muscle (110), and R-lipoic acid was more effective than R,S-lipoic acid and S-lipoic acid in preventing cataracts (111). However, all of the published human studies have used R,S-lipoic acid (racemic mixture). It has been suggested that the presence of S-lipoic acid in the racemic mixture may limit the polymerization of R-lipoic acid and enhance its bioavailability (52). At present, it remains unclear which supplemental form is best to use in clinical trials.
Safety
Adverse effects
In general, high-dose lipoic acid administration has been found to have few serious side effects. Intravenous administration of lipoic acid at doses of 600 mg/day for three weeks (112) and oral lipoic acid at doses as high as 1,800 mg/day for six months (113) and 1,200 mg/day for two years (76) did not result in serious adverse effects when used to treat diabetic peripheral neuropathy. There was no significant difference in the incidence of adverse events and serious adverse events in patients with diabetic neuropathy who took 600 mg/day of lipoic acid for four years compared to those in the placebo group (78). Oral intake of 2,400 mg/day for two weeks was also found to be safe in a pilot study that included participants with multiple sclerosis (95). Two mild anaphylactoid reactions and one severe anaphylactic reaction, including laryngospasm, were reported after intravenous lipoic acid administration (55). The most frequently reported side effects of oral lipoic acid supplementation are allergic reactions affecting the skin, including rashes, hives, and itching. Abdominal pain, nausea, vomiting, diarrhea, and vertigo have also been reported, and one trial found that the incidence of nausea, vomiting, and vertigo was dose-dependent (77). Further, malodorous urine has been noted by people taking 1,200 mg/day of lipoic acid orally (95).
Nutrient interactions
Biotin
The chemical structure of biotin is similar to that of lipoic acid, and there is some evidence that high concentrations of lipoic acid can compete with biotin for transport across cell membranes (120, 121). The administration of high doses of lipoic acid by injection to rats decreased the activity of two biotin-dependent enzymes by about 30%-35% (122), but it is not known whether oral or intravenous lipoic acid supplementation substantially increases the requirement for biotin in humans (123).
Yes, R is better in my trials. My trials are for toxin removal btw.
How much mgs of R-ALA gave better results, than how many mgs of mixed-ALA?
So in your case 100 mg of R-ALA gave better results than 600 mg of mixed ALA. That's quite a significant difference.
What other detox-methods addtional to ALA? Which might also be a influencing factor, compared to only taking ALA not particularly for detox.
So in your case 100 mg of R-ALA gave better results than 600 mg of mixed ALA. That's quite a significant difference.
New experiment, rLipoic works better than the ALA/RLA combination. rLA = 100mg, ALA/rLA is 600mg.
Reference 1 said:RLA in a salt form is considerably more bioavailable than an equivalent dose of [mixed racemic] LA (RLA + SLA). This indicates SLA may function as a competitive inhibitor in the absorption of RLA.
Lipoic acid is a cofactor for at least five enzyme systems.[3] Two of these are in the citric acid cycle through which many organisms turn nutrients into energy. Lipoylated enzymes have lipoic acid attached to them covalently. The lipoyl group transfers acyl groups in 2-oxoacid dehydrogenase complexes, and methylamine group in the glycine cleavage complex or glycine dehydrogenase.[3]
Wikipedia page on Lipoic acid said:As a result, lipoic acid is synthesized attached to proteins and no free lipoic acid is produced. Lipoic acid can be removed whenever proteins are degraded and by action of the enzyme lipoamidase.[8] Free [lipoic acid] can be used by some organisms [by using] an enzyme called lipoate protein ligase that attaches it covalently to the correct protein.