Thorne

Selenium

Thorne Selenium is a single-ingredient supplement delivering selenium in the form of selenomethionine, an organically bound amino acid chelate that is generally considered well absorbed compared to inorganic selenium sa…

£15

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Delivery includedArrives in 1 to 3 days30-day returns
ThorneSelenium
£151

Thorne Selenium is a single-ingredient supplement delivering selenium in the form of selenomethionine, an organically bound amino acid chelate that is generally considered well absorbed compared to inorganic selenium sa…

Why we love it

Thorne Selenium is a single-ingredient supplement delivering selenium in the form of selenomethionine, an organically bound amino acid chelate that is generally considered well absorbed compared to inorganic selenium salts. Selenium is an essential trace mineral that the body cannot synthesise on its own.

Good to know

  • A food supplement. Do not take more than the dose on the label.
  • Not a substitute for a varied, balanced diet and a healthy lifestyle.
  • Check with your doctor first if you are pregnant, breastfeeding, taking medication or under medical care.
  • Keep out of the reach of young children.
How to use

Take 1 capsule daily, as directed on the packaging. Selenium is typically taken with a meal to aid tolerability. Do not exceed the stated dose without guidance from a clinician, as selenium has a relatively narrow therapeutic window.

More about it

Thorne Selenium is a single-ingredient supplement delivering selenium in the form of selenomethionine, an organically bound amino acid chelate that is generally considered well absorbed compared to inorganic selenium salts. Selenium is an essential trace mineral that the body cannot synthesise on its own. It is incorporated into selenoproteins, a family of enzymes that include glutathione peroxidases - key players in the body's antioxidant defence - and iodothyronine deiodinases, which convert the thyroid prohormone T4 into the active form T3. These mechanisms explain why selenium is routinely discussed in the context of thyroid health, particularly in conditions such as Hashimoto's thyroiditis and Graves' disease, where it is studied for its potential to modulate thyroid peroxidase antibody levels. Beyond thyroid function, adequate selenium status is linked to normal immune cell activity and to the protection of cells from oxidative stress. Selenium intake from food varies considerably with geography, and soils in parts of Europe - including the UK - tend to be low in selenium, making dietary shortfall more common than is often appreciated. This supplement suits those with confirmed or suspected low selenium status, individuals managing thyroid conditions under medical supervision, and anyone whose diet is light in selenium-rich foods such as Brazil nuts, seafood, or organ meats. Thorne is a brand with a long-standing reputation for formulation rigour and clean excipient profiles, which is why it features across several of our nutrition protocols.

Delivery and returns

Standard UK delivery included on every order, 1 to 3 working days after dispatch.

Next working day for £25 when you order by 12pm. Orders placed before 12pm on a working day leave the same day. Later orders leave the next working day.

You can return unopened and unused items within 30 days of delivery. This does not affect your statutory rights. Read the delivery and returns terms

or call 020 3951 3429

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Your questions

Who is most likely to benefit from a selenium supplement?

People with confirmed low selenium status via blood test, those managing autoimmune thyroid conditions under medical care, and individuals whose diets are low in selenium-rich foods — such as those eating little seafood or nuts — are the most relevant candidates. UK soil is notably selenium-poor, so dietary intake is often lower here than in North America.

How does selenomethionine differ from other forms of selenium?

Selenomethionine is selenium bound to the amino acid methionine, which is how selenium occurs naturally in plant foods. It is generally considered to have good bioavailability compared to inorganic forms such as sodium selenite or selenate, and it is the form most frequently used in clinical research on thyroid health.

Is it safe to take selenium long-term?

Selenium has a narrower gap between adequate intake and excess than most minerals, so long-term use at higher doses carries a risk of selenosis. At a standard daily dose this risk is low, but it is worth checking your level via a blood test before supplementing and reviewing periodically with your GP or clinician, particularly if you also eat Brazil nuts regularly.

Can I take this alongside my thyroid medication?

Selenium supplements are generally considered compatible with thyroid medications such as levothyroxine, but you should always inform your prescribing doctor before adding any supplement to your routine, especially when managing an active thyroid condition.

How long before I might notice a difference?

Selenium works at a cellular and enzymatic level, so changes are unlikely to be felt acutely. In clinical studies on thyroid autoimmunity, measurable effects on antibody levels are typically assessed over several months. Regular monitoring via blood tests is the most reliable way to track progress.

In their words

Overall

4.941 reflections
1 to 6 of 41 reflections
HB

Part of my morning stack now

6 months ago

Take this alongside my magnesium and vitamin D every morning. Wasn't expecting much but my thyroid numbers have been steadier since I added it in. GP was actually pleased at my last check-up.

T

Simple, clean, does the job

6 months ago

No fillers I'm worried about. Just the one ingredient. Takes about 30 seconds to research why UK diets tend to be low in selenium and suddenly this made a lot of sense to add in.

CR

Good supplement, but the capsule is a bit large

6 months ago

Works well as far as I can tell — my naturopath recommended it for thyroid support and I've been on it about 8 weeks. Only gripe is the capsule size, it's slightly bigger than I'd like for a daily tablet. Not a dealbreaker but worth noting.

OF

Fits neatly into my routine

6 months ago

Take it with breakfast, that's it. Subtle effects — nothing dramatic — but my energy feels a bit more even across the day. I've been managing Hashimoto's for a few years and my integrative doctor suggested this. Glad I made the switch from a cheaper brand.

JW

7 months ago

Recommended by my endocrinologist as a top-up while living in the UK. Nice to find it available here rather than having to import.

DF

Quietly doing its job

7 months ago

Started this after a blood test flagged my selenium was on the low side — GP wasn't concerned enough to prescribe anything but suggested supplementing. First impression was how small and easy to swallow the capsule is, which sounds minor but I've abandoned bulkier supplements before. A few weeks in and my energy feels steadier. Can't attribute that to one thing, but I haven't changed much else. At this price point it's an easy add-on.

Pairs well with

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