2% vs. 5% Lugol's Iodine Solution: Which Strength Do You Need?

"Just get the 5%, it's stronger" is common advice — but with a formula this trusted, dialing in the right strength for you matters more than defaulting to the biggest number.

The Short Answer

2% Lugol's Solution delivers about 2.5mg of iodine/iodide per drop, while 5% delivers about 6.25mg per drop. The 2% is ideal for precise, confident dosing when you're getting started; the 5% is the efficient choice once you know your target and want fewer drops per serving.

Drop-to-Milligram Breakdown

Both strengths come from the same trusted Lugol's Solution collection and use identical dilution ratios — the only variable is how much iodine is packed into each drop.

Choose your strength

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Made in the U.S.A. in amber glass dropper bottles. 2% gives the finest control per drop; 5% is the classic strength.

2% Lugol's Solution
2oz amber glass · finest control per drop
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2oz amber glass · the classic strength
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Compare all 6 strengths, 2% to 20% →

Frequently Asked Questions

Should I start with 2% or 5% Lugol's Solution?

Start with the 2% if you're new to iodine drops — it lets you adjust your dose in smaller, confident increments. Move to the 5% once you know your target dose and want fewer drops per serving.

How much stronger is 5% Lugol's Solution than 2%?

Two and a half times. The percentage reflects the concentration of the solution, so one drop of 5% (about 6.25mg) delivers 2.5 times the iodine of one drop of 2% (about 2.5mg).

Can I just take fewer drops of the 5% instead of buying the 2%?

You can, but many people find the 2% easier to dose accurately when working with smaller amounts, since each drop is about 2.5mg instead of 6.25mg — it's a great way to build confidence with your routine.

Shop Lugol's Solution — the traditional, trusted way people have supported their iodine intake for over 200 years.

This article is for general educational purposes only and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease, and is not a substitute for advice from a qualified healthcare provider — especially if you are pregnant, nursing, taking thyroid medication, or managing a thyroid condition.

Ryan Whitfield writes about iodine dosing and protocol basics for the Iodine Journal.

This article is part of our complete comparison guide to Lugol's Solution, Liquid Iodine, and Nascent Iodine.