R-Lipoic acid (R-ALA, natural enantiomer, free acid)
R-Lipoic acid (R-ALA, natural enantiomer, free acid) is a unrated form of Alpha-Lipoic Acid, used in 206 on-market products .
Why this tier: The naturally occurring enantiomer; the free acid is described as unstable/poorly soluble. In one randomized crossover (n=20, progressive MS), 600 mg R-LA was bioequivalent in R-LA AUC/Cmax to 1,200 mg racemic R,S-LA and caused fewer GI side effects (Cameron 2020); a pilot (Keith 2012) found variable, age-dependent differences. No outcome trial compares them, so it is not ranked.
Source: Cameron M et al. 2020, J Clin Pharmacol 60(8):1099-1106, PMID 32212340; Keith DJ et al. 2012, Pharmacol Res 66(3):199-206, PMID 22609537; Carlson DA et al. 2007, Altern Med Rev 12(4):343-351, PMID 18069903 (background statement; study itself tested the sodium salt)
Trend
Brands using this form
| Brand | Products |
|---|---|
| BulkSupplements.com | 7 |
| Life Extension | 6 |
| Xtendlife | 6 |
| Geronova Research | 5 |
| NFH | 5 |
| NuMedica | 5 |
| Source Naturals | 5 |
| BioAnue | 4 |
| Doctor's Best | 4 |
| NutriCology | 4 |
| SAN | 4 |
| SuperSmart | 4 |
| Allergy Research Group | 3 |
| BPI Sports | 3 |
| Controlled Labs | 3 |
| Davinci Laboratories | 3 |
| Jarrow Formulas | 3 |
| Moss Nutrition | 3 |
| NaturesPlus | 3 |
| Neuropathy Treatment Group | 3 |
| Nutra BioGenesis | 3 |
| Ryno Power | 3 |
| SNAC Nutrition | 3 |
| Swanson | 3 |
| TumoRx | 3 |