Answer · DMSA and DMPS
DMSA vs DMPS
DMSA (succimer) and DMPS (unithiol) are water-soluble relatives of the older drug BAL, studied as metal-binding agents. Aposhian’s 1983 review reported that DMSA was less toxic than DMPS in mouse tests, and that DMSA appeared to move more organic mercury while DMPS moved more inorganic mercury. In the United States the prescription form of DMSA is FDA-approved for lead poisoning in children, and DMPS is not an FDA-approved drug.
By Stephen Heuer, B.S. Nutripath · 36+ years · Published · Updated
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What is DMSA?
DMSA is meso-2,3-dimercaptosuccinic acid. The prescription name is succimer. The FDA label for Chemet describes it as an oral heavy-metal chelating agent that forms a water-soluble chelate with lead and increases urinary lead excretion. That approval is for lead poisoning in children, at the blood-lead levels and doses on the drug label. It is not a license to self-treat with a supplement.
Aposhian describes DMSA as a water-soluble analog of British Anti-Lewisite. Unlike BAL, it has limited lipid solubility and can be given by mouth. The same review cites mouse intraperitoneal LD50 figures of 13.58 mmol/kg for DMSA, 5.22 for DMPS, and 0.73 for BAL, which is the basis for calling DMSA the less toxic of the two in that comparison.
What is DMPS?
DMPS is sodium 2,3-dimercapto-1-propanesulfonate. Petrunkin reported the compound in 1956, and it became an official drug in the Soviet Union under the name Unithiol. Aposhian reviews that history and groups DMPS with DMSA as an oral, water-soluble metal-binding agent studied for arsenic, lead, and mercury.
DMPS is not the FDA-approved lead drug. A capsule of DMPS from a supplement catalog is not Chemet, and it is not a protocol for mercury poisoning.
How did the pharmacology review compare them?
Aposhian’s comparison, which is a review of animal and clinical literature available by 1983, is the clearest head-to-head summary still cited. Both agents are excreted by the kidney. Both can raise urinary copper and zinc while they are being taken, and that effect was described as dose-dependent and reversible after the drug stopped.
On mercury, the review’s reading was that DMSA looked more effective overall at removing mercury, with DMSA taking more organic mercury and DMPS more inorganic mercury. That is a reviewer’s synthesis, not a new head-to-head trial, and it is not a reason to pick a capsule without a physician who treats poisoning.
Is the supplement the same as the prescription drug?
No. Chemet is a specific 100 mg succimer capsule with an FDA label, a pediatric lead indication, and a published dosing schedule for that indication. The DMSA 25 mg listing and the DMPS 25 mg listing in this catalog are supplement products. They are not Chemet, and this page does not repeat a drug dose.
Poisoning treatment belongs with a licensed clinician and, when a drug is indicated, with the approved product. The detox and chelation hub only maps which bottles are in the catalog.
Which sources is this based on?
Two sources carry the comparison. The review is from 1983. The FDA label is the regulatory fact about succimer.
- Aposhian HV. DMSA and DMPS—water soluble antidotes for heavy metal poisoning. Annu Rev Pharmacol Toxicol. 1983;23:193-215. doi:10.1146/annurev.pa.23.040183.001205
- FDA. CHEMET (succimer) capsules prescribing information. NDA 019998. Label revised 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/019998s021lbl.pdf
Frequently asked questions
What is the difference between DMSA and DMPS?
Both are water-soluble metal-binding agents related to BAL. In Aposhian’s 1983 review, DMSA was less toxic in the mouse LD50 comparison, and the mercury discussion assigned more organic mercury to DMSA and more inorganic mercury to DMPS. Only prescription DMSA (succimer, Chemet) is FDA-approved, and that approval is for lead poisoning in children.
Is DMPS FDA-approved?
No. DMPS was an official drug in the Soviet Union as Unithiol. It is not an FDA-approved drug in the United States. Succimer, which is DMSA, is the approved oral chelator sold as Chemet.
Can I use the DMSA capsule on this site as Chemet?
No. Chemet is a prescription 100 mg succimer drug with its own label. The DMSA capsule in this catalog is a different product and a different strength. This page does not give a chelation dose.
Related on this site
Educational information only. Chelation for poisoning is medical care. Synergistic Nutrition does not diagnose, treat, cure, or prevent disease, and these capsules are not the prescription drug Chemet.
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