About Kelp
A brown seaweed (e.g. Laminaria, Ascophyllum) used as a natural source of iodine and trace minerals. The main physiological effect is iodine delivery, which can be excessive and variable, potentially disrupting thyroid function. Marketed weight-loss claims are unsupported. ⚠️ Excess iodine can disrupt thyroid function; avoid in pregnancy and with thyroid medication. Kelp may also accumulate arsenic and other heavy metals.
What Kelp supports
- Seaweed used as a natural iodine source
How much Kelp to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
150–600
mg
Used mainly as a natural iodine source; iodine content is the active consideration and can be very high (risk of excess).
Clinical evidence
Limited clinical evidence. Primarily an iodine source; variable iodine can disrupt thyroid
Reference