4.5· 371 reviews

Sea Kelp Thyroid Health

A daily iodine supplement sourced from Atlantic sea kelp, formulated to support healthy thyroid function and normal metabolic activity.

  • Vegan
  • Non-GMO
  • Soy-Free
  • Gluten-Free
  • Made in USA

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Supplement Facts

Supplement Facts

Serving Size: 1 Tablet

Servings Per Container: 100

Nutrient Amount Per Serving % DV*
Iodine (from Kelp, potassium iodide) 225mcg 150%

Other Ingredients: Cellulose, stearic acid (vegetable source), silica, calcium stearate (vegetable source).

How to Use
Take 1 tablet daily, preferably with food.
Research

The studies below reference peer-reviewed research on the key active ingredients in this product. These are ingredient-level studies.

Iodine (from Kelp, potassium iodide)

  • Ma et al., 2016 · European Journal of Nutrition

    Randomized controlled trial; n=112; 6 months; participants with mild iodine deficiency

    Participants with mild iodine deficiency who received iodine supplementation showed statistically significant improvements in urinary iodine concentration and thyroid function markers compared to those who received no supplementation; results are specific to deficient populations and may not reflect outcomes in iodine-sufficient individuals.

  • Clark et al., 2003 · American Journal of Clinical Nutrition

    Randomized, double-blind, placebo-controlled crossover trial; n=36; multiple treatment periods; healthy adults

    Healthy adults who received kelp as a dietary iodine source showed measurable increases in urinary iodine excretion compared to those who did not receive kelp; the study authors noted that high doses of kelp-derived iodine produced elevations in serum thyrotropin, indicating a potential dose-dependent effect on thyroid function.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

How it works

Every ingredient, chosen with intention.

Here's what's in this bottle - and why each ingredient earned its place in the formula.

  1. Iodine

    Iodine from sea kelp and potassium iodide

    A trace mineral the thyroid gland uses to synthesize T3 (triiodothyronine) and T4 (thyroxine) hormones, which regulate metabolism, energy production, and other physiological processes throughout the body.

    Why we chose it

    Sourced from two complementary forms: sea kelp for the whole food plant matrix, and potassium iodide for precision and consistency. Kelp's iodine content varies naturally harvest to harvest, the potassium iodide standardizes the total to a reliable 225mcg in every tablet.

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Pairs well with

Complete your routine.

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4.5

Vegan B12

A 1,000mcg B12 tablet formulated to support energy metabolism and nervous system function, especially for those following a plant-based diet.

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Whole Food Iron

A whole-food iron supplement chelated with rice protein for gentle absorption, formulated to support healthy red blood cell production.

Questions, answered

What customers often ask.

Why do vegans need to supplement iodine?
Iodine in the food supply comes mostly from dairy (where cows are supplemented) and seafood. Plant-based diets that avoid both, and don't regularly use iodized salt, tend to fall short of the daily reference amount. A consistent daily iodine source helps your body maintain the levels your thyroid relies on.
Can I take this if I have a thyroid condition?
Please consult your healthcare provider before supplementing iodine if you have a diagnosed thyroid condition or are on thyroid medication. Iodine intake, even at moderate levels, can interact with certain thyroid conditions and medications in ways that require professional monitoring.
Why does this use both kelp and potassium iodide?
Kelp's natural iodine content varies from harvest to harvest, making it unreliable as a sole source. Potassium iodide standardizes the total to a consistent 225mcg per tablet. The kelp contributes the whole plant matrix; the potassium iodide makes the dose precise.
How long until this makes a difference?
Research in participants with mild iodine deficiency shows that iodine status can normalize within weeks of consistent supplementation. For broader thyroid-related changes, the timeline is longer and depends on individual baseline levels, your healthcare provider can test iodine status if you're curious about your starting point.
When should I take this tablet?
Any time of day works. There's no significant timing advantage for iodine. Many people take it with breakfast as part of a morning supplement routine. You can take it with or without food.
Can I stack this with Vegan B12?
Yes, iodine and B12 are two of the most common nutritional gaps on a fully plant-based diet. Taking both daily addresses two different needs: iodine for thyroid function, B12 for energy metabolism and nervous system support. They don't interact.

What customers say

Results, backed by reviews.

  • 5 stars: 249 (67%)
  • 4 stars: 69 (19%)
  • 3 stars: 33 (9%)
  • 2 stars: 18 (5%)
  • 1 star: 2 (1%)
L
LINDA Q.
Useful for my vegan routine

I eat mostly vegan and had been trying to be more deliberate about iodine instead of assuming I was getting enough from random foods. This fit easily into my morning routine. The tablet is small and has no strong seaweed smell, which I was honestly worried about after opening the package. I did not buy it expecting a dramatic change in a week. I just wanted a simple plant-based iodine source that I could take consistently and mention at my next check-in. After about two months I have been happy with it. The bottle is straightforward, the directions are clear, and it has not bothered my stomach. I appreciate products that do not make a giant promise and are just easy to use every day.

M
Melissa R.
hair shedding slowed

I bought this for iodine support after reading more about plant based diets. Took about 6 weeks before I noticed anything, but my nails feel stronger and my hair brush is less scary. I also like that the capsules are small because i hate giant pills. I am careful with thyroid-related stuff and checked in with my doctor, so this is just my experience, not advice. For me it has been a simple daily add-on. No nausea, no seaweed burps, no weird taste. The hair thing was gradual, like one day I realized the shower drain was not looking as dramatic. That was enough for me to order another bottle.

S
S. Chen
Good for plant-based athletes

I run on a plant-based diet and had no idea iodine was an issue. Blood panel flagged it. Fixed it with this supplement. Energy during runs improved noticeably after 6 weeks.

R
Robert
Hair texture changed too

Not just less shedding. My hair is growing back thicker and shinier. The texture changed. My stylist asked what I was doing differently. Sea kelp was the main change.

J
J. Williams
Whole food source matters to me

I specifically wanted a whole-food iodine source rather than synthetic potassium iodide. Kelp delivers iodine naturally. My system responds much better to this form. Levels are stable and I feel good about what I'm taking.

S
S. Chen
Worth every penny

I spent two years and probably $3000 on doctors, tests, and supplements that didn't help. Sea kelp cost me $25 and fixed what most of the expensive interventions didn't touch. Iodine deficiency is underdiagnosed and underappreciated. If you're on a plant-based diet and feeling chronically tired, foggy, cold, and your hair is thinning — get your iodine levels checked and consider this supplement. It was the missing piece for me.

L
Linda
Thyroid panel improved

My functional medicine doctor checks my thyroid quarterly. Since adding sea kelp my free T3 improved and TSH moved down toward optimal. Small change that made a meaningful difference.

l
ljohnson
My naturopath recommended it

My naturopath suggested sea kelp for iodine support before any medication discussion. Glad I followed the advice. Three months later my TSH is in the best range it's been in two years.

C
CAROL S.
Doctor was surprised

My TSH was creeping up for two years. Added this to my routine. Last bloodwork it had moved back into optimal range. My doctor asked what I'd changed.

S
Stephanie
Doctor approved for Hashimoto's

I have Hashimoto's and was nervous about iodine. My endocrinologist reviewed this supplement and said a low dose kelp was appropriate for me — one capsule every other day under her supervision. My energy is better and no flare in 3 months. If you have an autoimmune thyroid condition, please check with your doctor before adding iodine. But it can be done safely. My experience has been positive.

S
Sofia
No fishy smell

Some kelp supplements smell really bad. This one is minimal. Easy to take daily. Been consistent 10 weeks and my thyroid panel is stable.

D
David
Nails got stronger too

Bonus I wasn't expecting: my nails stopped peeling and breaking. Thyroid health affects everything apparently — hair, nails, skin all improved since starting this. The nail change was the one that surprised me most.

B
Barbara
Underrated supplement

People don't talk about iodine enough. Most plant-based eaters are quietly deficient. This supplement fixed a problem I had for years and didn't know about.

M
Maria
My stylist noticed before I told her

I want to write this out because hair loss is really emotionally difficult and I want other people who are in the same place to know that this helped me.

I was losing somewhere between 200 and 400 hairs a day. I know because I counted. My hair went from thick and healthy to visibly thin at the temples and crown over about 8 months. Dermatologist said it was likely telogen effluvium and checked my iron, ferritin, thyroid — all normal range. But my iodine and thyroid ultrasound hadn't been checked.

I found my iodine levels on my own through functional medicine. Low-normal. Started sea kelp in February.

By week 6 the shedding slowed. By week 10 I had baby hairs. At week 14 my stylist asked what I was doing differently. I hadn't told her I was trying anything. She said my density was noticeably better. That external observation from someone who wasn't looking for improvement meant more to me than anything I'd measured myself.

D
DIANE F.
Better than synthetic iodine

Tried potassium iodide and felt off on it. Switched to this whole-food kelp form and my body responds much better. Gentler on my system and my thyroid markers improved at my last panel.

K
Karen Roberts
Brain fog lifted

Brain fog lifted. Turned out to be iodine. Simple fix.

C
Chris
Small capsule big difference

Capsule is easy to swallow, minimal smell. Been taking 2 months. Thyroid feels supported, energy is steady, hair is thicker.

D
David
Energy is completely different

I thought being tired all the time was just me. Turns out iodine deficiency. Two months on this and I'm a different person. Morning energy is real now.

M
Michael
Life changing is the right phrase

I don't use 'life changing' lightly. Having chronic fatigue and brain fog changes how you show up at work, with your family, in your life. Two months on sea kelp and most of those symptoms are gone. The iodine was the missing piece.

l
ljohnson
Easy to recommend

Recommended this to my plant-based sister after my own results. She's 6 weeks in and already noticing better energy and less brain fog. The iodine gap in plant-based diets is real.

G
GINA M.
Consistent for 3 months

Been taking every morning since January. Thyroid feels stable, energy is good, hair is healthy. No plans to stop.

M
Maria
Gentle and effective

I have a sensitive system and was nervous. Started with half a capsule for two weeks. No issues. Gradual real improvement over 8 weeks.

d
dchen_
Paired with selenium

Taking this alongside selenium as a comprehensive thyroid support approach. My endocrinologist said my levels look good at my last visit. The combination matters.

A
Ashley R.
TSH normalized

TSH finally in optimal range after 18 months of creeping up. Sea kelp was the change.

R
Robert
Finally found vegan iodine that works

I rejected synthetic iodine supplements for years. This whole-food kelp form sits right with me. Levels responded and my nutritionist is happy with my panels.

a
amandab_
Changed how I feel every single day

Before this supplement I was exhausted, my hair was falling out in fistfuls, I was freezing all the time, and I couldn't concentrate through a full workday. My doctor said subclinical hypothyroidism — nothing severe enough for medication but clearly affecting my quality of life.

I went down the rabbit hole on plant-based iodine deficiency and realized I hadn't been eating iodized salt or seaweed for years. My diet was genuinely iodine-poor. Started this supplement in January.

Week 4: energy slightly better. Week 6: brain fog lifting. Week 8: hair shedding noticeably less. Week 12: my thyroid markers improved meaningfully at my bloodwork. Week 16 (today): I feel like myself again. Warm, sharp, energized. I cannot overstate how much iodine deficiency was affecting my daily life.

T
T. Okafor
Warmer, sharper, more energy

Used to be cold all the time. Wore a sweater in the office year round. Colleagues noticed. Three months on sea kelp and I'm warm again. Thyroid was clearly struggling and the iodine was what it needed.

J
JAMES W.
Metabolism picked up

Was doing everything right diet and exercise-wise but felt like my metabolism was broken. Added sea kelp and within 6 weeks things started moving again. Weight is easier to manage and I have more energy throughout the day.

L
Linda
Postpartum hair loss help

Lost so much hair after having my baby. Turns out iodine was part of the picture. Started these at 4 months postpartum and the regrowth is real. Wish I'd known sooner.

A
A. Patel
Skin is glowing

Thyroid health affects skin apparently. Since adding sea kelp my skin is noticeably more dewy and less dull. Not what I expected but a welcome bonus.

J
Jennifer
Hair is back

Hair is back. That's it. That's the review.

M
Michael
Essential for plant-based eaters

Essential if you're vegan and not eating seaweed regularly. My levels confirm it.