How long before I notice anything?

Give it three months, then re-test. Nutrient levels build up slowly. Most people who feel a difference feel it between week three and week six, and the 60-day guarantee covers that window.

Most people already get iodine from salt and food. In Hashimoto's, adding more can push the thyroid the wrong way, which is why we left it out, along with kelp.

Because ten ingredients at research-based doses do not fit in one capsule. Take the three together, with a meal.

Who should not take it?

Anyone pregnant or breastfeeding should ask their doctor first. So should anyone with hyperthyroidism or hemochromatosis. If you take other supplements, check for overlap on selenium and vitamin D.

Is it just an expensive multivitamin?

A multivitamin is built for the general population, with small doses and iodine. Core Axis is built for one condition, at research-based doses, in the active forms, without iodine. Buying the same ten ingredients separately means ten bottles and about $160 to get started.

Thyroid support built for Hashimoto's.

Ten nutrients at research-based doses, formulated with an endocrinologist. No iodine. Take it alongside your levothyroxine, four hours apart.

Start the monthly plan, $29.95

4.8 on AmazonFormulated with an endocrinologist60 days, money back

An endocrinologist read our label on camera

Dr. Flaviu Pătrășcanu treats thyroid patients every week. He helped build this formula. Here is what he looks for on a label, and who this is not for.

Read the full formulation

Dr. Flaviu Pătrășcanu, MD, Endocrinologist. Paid medical consultant to Core Axis.

As featured in

Three things to check on any thyroid supplement label.

Most multivitamins use folic acid and cyanocobalamin. Your body has to convert them before it can use them, and about one person in three carries a gene variant that makes that conversion slow. We use methylfolate and methylcobalamin, the forms that skip the step.

Most others

Folic acid
Cyanocobalamin

Needs converting first

Core Axis

L-5-MTHF
Methylcobalamin

Ready to use

Every dose on the label.

Ten ingredients at the doses printed on the bottle. Seven of them the typical thyroid supplement leaves out.

Check, included. Cross, usually missing.

Core Axis ingredients compared with the typical thyroid supplement
Ingredient and daily dose		Typical thyroid supplement
Selenium100 mcgas L-selenomethionine
Zinc15 mgas zinc bisglycinate
Vitamin B12500 mcgas methylcobalamin
What most thyroid supplements leave out
Myo-Inositol600 mgpharmaceutical grade
Vitamin D350 mcgas cholecalciferol, 2,000 IU
Vitamin B63 mgas P-5-P, the active form
Methylfolate400 mcgas L-5-MTHF
Vitamin C100 mgas calcium ascorbate
Magnesium150 mgas magnesium bisglycinate
Glutathione100 mgas S-acetyl-glutathione
And what we leave out
No iodine or kelp	None	9 of 10 contain it

Doses per daily serving of three capsules. Typical thyroid supplement means what most of the ten best-selling thyroid formulas on Amazon contain, labels checked October 23, 2026.

B12 is listed at 20,833% of the daily value on purpose. The body absorbs about 2% of a dose, and B12 has no upper limit.

Plant-based capsule, no dyes or fillers. Every batch tested by Eurofins, certificates on the formulation page.

Why these ten, and in these forms

Clément, founder of Core Axis, in Hakone

I built this because nothing on the shelf worked for me.

I was diagnosed with Hashimoto's at 28. Levothyroxine brought my TSH back into range, and most of my symptoms stayed. The fatigue, the brain fog, the cold. None of the twelve multivitamins I tried changed anything.

So I spent two years reading the trials, then found an endocrinologist who treats thyroid patients every week and asked him to build the formula with us. Every dose was then checked against the research by Elena Vayndorf, PhD. Core Axis is what I take with lunch.

Clément

Founder, Core Axis

Dr. Flaviu Pătrășcanu, MDEndocrinologist · Formulated the supplementWatch his full interview on YouTube ↗

Elena Vayndorf, PhDResearch Scientist · NIH · Reviewed every doseAbout Elena →

What the first customers wrote.

4.8 out of 5 · 25 ratings on Amazon

Paid partnership

Jess, takes Core Axis daily

Paid creator. She takes the product and says so in the video.

“I'm not on medication due to the fluctuation of my numbers. The Myo-Inositol 600mg is what is recommended after studies and no digestive issues after taking them.”

Julie, Amazon

“It has a lot of compounds within it so I cannot combine with my normal multivitamin. At least this will save me money.”

Christian Family, Amazon

“I noticed more focus, improved energy, and an overall sense of well-being. Of course, individual results may vary, but I was pleased with my experience.”

Ally Cat, Amazon

Reviewers received the product free through Amazon Vine. Quoted as written, shortened for length. Individual results vary.

Choose your plan.

“Give it three months, then re-test.”

Dr. Flaviu Pătrășcanu, MD, Endocrinologist

Free

Included with your plan

The Hashimoto's Protocol Guide

Which labs to ask for, the daily routine around the capsules, and a 90-day journal to track what changes.

4.8 out of 5 on Amazon, 25 ratings

60 days, money back.

On your first order, nothing to send back. How it works

Free US shipping · Pause or cancel anytime

A bottle of Core Axis Thyroid Support, 90 capsules

Ten ingredients90 capsules30 days

Questions people ask before they order.

Yes, four hours apart. Levothyroxine when you wake up, Core Axis with lunch. It never replaces your medication.

From the journal

All articles →