Clinical Reference · Heavy Metals
Mercury on the plate
Methylmercury doesn't spread evenly through the ocean. It concentrates — step by step, predator by predator — until a single fillet can carry a month of your tolerable intake.
Highest mean concentration on record, Gulf of Mexico tilefish
FDA action level for methylmercury in commercial seafood
EPA reference dose
Half-life of methylmercury in blood. One meal is not one bad day.
Section 02 · Biomagnification
Mercury climbs the food chain
Total magnification from seawater to apex predator. Bars are shown on a logarithmic scale — on a linear scale the first four levels would be invisible.
Section 03 · FDA Monitoring Program
Mean methylmercury by species
For contrast — low-mercury choices
Section 04 · Exposure Model
What one serving actually costs you
| Species | µg / serving | Days of RfD | Servings / mo |
|---|---|---|---|
| Tilefish (Gulf of Mexico) | 190.9 | 27.3 | 1.10 |
| Swordfish | 169.2 | 24.2 | 1.24 |
| Shark | 166.4 | 23.8 | 1.26 |
| King mackerel(not Atlantic mackerel) | 124.1 | 17.7 | 1.69 |
| Bigeye tuna(often sold as ahi) | 117.1 | 16.7 | 1.79 |
| Orange roughy(lives 100+ years) | 97.1 | 13.9 | 2.16 |
| Marlin | 82.5 | 11.8 | 2.55 |
| Albacore tuna(canned white) | 59.5 | 8.5 | 3.53 |
| Canned light tuna (skipjack) | 21.4 | 3.1 | 9.80 |
| Cod | 18.9 | 2.7 | 11.13 |
| Atlantic mackerel | 8.5 | 1.2 | 24.71 |
| Salmon | 3.7 | 0.5 | 56.15 |
| Sardines | 2.2 | 0.3 | 95.02 |
| Shrimp | 1.5 | 0.2 | 137.25 |
| Scallops | 0.5 | 0.1 | 411.76 |
Values under one serving per month indicate a species better treated as an occasional exception than a rotation staple. Pregnancy, conception planning, and childhood carry stricter thresholds.
Section 05 · Substitutions
The answer is not less seafood. It is seafood from lower down the chain — where the EPA and DHA are just as good and the mercury is a rounding error.
Section 06 · Clinical Framework
How we handle this at Peak Human
Test before you treat
Whole blood mercury reflects recent intake over roughly three months; hair mercury a longer window. Ordered as part of the heavy metals panel.
Time does most of the work
With a ~50-day blood half-life, removing high-mercury species clears most of the burden in four to six months. Re-draw at 90 days after dietary change.
Chelation is not step one
Reserved for genuine toxicity confirmed on testing and supervised accordingly. For the elevated-but-not-toxic range, exposure removal is the intervention.
Selenium and the whole fish
Many low-mercury species are selenium-rich and selenium binds mercury in tissue. Assessed alongside omega-3 index.
Section 06b · Treatment Pathway
When exposure removal isn't enough
Chelation is considered only when blood mercury is elevated on testing and there is meaningful ongoing or historical exposure. It is not a routine longevity intervention and it is not a first step. For elevated but asymptomatic mercury, removing the exposure and re-testing at 90 days is the intervention.
The two agents
DMSA
Oraldimercaptosuccinic acid / succimer
- —Binds mercury in the extracellular compartment and increases urinary excretion
- —FDA-approved for lead poisoning in children; use for mercury is off-label
- —Limited penetration into the central nervous system
DMPS
Intravenousdimercaptopropanesulfonic acid
- —High affinity for mercury; concentrates in renal tissue where mercury is preferentially stored
- —Not an approved marketed drug in Canada or the United States; obtained through compounding
- —Physician-supervised administration only
Cycle structure
One DMSA capsule each morning, empty stomach, with hydration
DMPS IV, 10–15 minutes. At least 300 mL water afterward. Hold urine 1–2 hours.
Break of 4 to 7 days before the next cycle
Most patients complete 5–10 cycles depending on baseline levels and response
Body weight is required before each IV to calculate the DMPS dose.
Monitoring
- 01Baseline whole blood mercury before cycle 1
- 02Blood mercury every 4 weeks following the final IV
- 03Renal function throughout — mercury clears renally and chelation increases renal load
- 04Essential trace minerals: zinc, copper, selenium, magnesium. Neither agent is selective for mercury, and both deplete essential metals. Repletion is part of the protocol, not an afterthought.
Contraindications and cautions
- •Pregnancy and breastfeeding
- •Significant renal impairment
- •Known hypersensitivity to thiol chelators
- •Uncorrected essential mineral deficiency — correct before starting
Treatment response
Average reduction in provoked urinary mercury across a full course, in our patient group. This is an internal treatment-response marker, not a diagnostic threshold. Provoked post-chelation urine testing is not a validated diagnostic standard, and chelating agents increase urinary metal excretion by design. We track the trend across cycles because it is informative. Diagnosis rests on whole blood mercury together with dietary and exposure history.
Cost per cycle
Travel and in-home service fees additional. Delivered in-clinic or at home with advance scheduling; capsules are provided before the cycle begins.
Chelation therapy is prescribed and supervised by a physician following testing. This page describes a treatment offered to assessed patients and is not a recommendation for any individual. It is not a substitute for clinical evaluation.
Sources
U.S. FDA Monitoring Program mean methylmercury concentrations (ppm); U.S. EPA methylmercury reference dose 0.1 µg/kg/day; FDA action level 1.0 ppm.
Disclaimer
Educational content, not a substitute for individualized medical advice. Species means conceal wide individual variation. People who are pregnant, planning conception, breastfeeding, or feeding young children should follow the joint FDA/EPA fish advice. Discuss testing and dietary change with your physician.