Thyro-L (levothyroxine sodium) Powder for Horses, 1-lb

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About This Item

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Thyro-L is a powder supplement prescribed to aid in the correction of conditions associated with a low-circulating thyroid hormone in horses. It may also be helpful in the adjunct treatment for weight loss caused by insulin resistance, as well as aid in the prevention of laminitis and hyperlipidemiaan abnormally high concentration of fats or lipids in the blood.

We directly source prescription medications from manufacturers and wholesale distributors registered with the FDA and licensed by applicable state boards. Guaranteed genuine, and where applicable, backed by the manufacturer.

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4.8
Rated 4.8 out of 5 stars
372 Ratings
Terms & Conditions

105 Customer Reviews

Always consult a veterinarian about your pet’s health needs. Customer reviews should not be used as medical advice.

Rated 5 out of 5 stars
By Katlin on Dec 7, 2025

Energy

I was a bit worried about trying this before winter but my gelding has tons of energy nowe and dropped a healthy amount of weight. He was on the thyrol for 5 weeks

I was a bit worried about trying this before winter but my gelding has tons of energy nowe and dropped a healthy amount of weight. He was on the thyrol for 5 weeks and my farrier came out and said “wow he grew a ton since last trim.” So I told her I had started the thyroid medication and before that he was growing slow and I was giving him all the right things to improve hoof healthy but he was still growing slow. He has been on a forage based diet for over a year with vermont blend supplement which helped but then we hit a wall with slow growth. The thyroL got us through that wall and we are convinced it helped with circulation and more movement which increased his blood flow to his hooves and that is why he grew so much over 5 weeks. I went to a ranch clinic and he really worked hard for me and it felt good. I will continue with this product

Rated 5 out of 5 stars
By Jessica on Dec 6, 2025

It worked!

Horse was just holding on to weight and was struggling to drop those extra pounds. Dr prescribed this and it seems to done the trick to jump start his metabolism

Horse was just holding on to weight and was struggling to drop those extra pounds. Dr prescribed this and it seems to done the trick to jump start his metabolism and get it back on track.

Rated 5 out of 5 stars
By Jacqueline on Nov 19, 2025

Great supplement for treating metabolic horses

Our horses have been prescribed Thyroid L, pergolide and InsulinWise. I wish i could buy all three on Chewy. Thyroid L comes in two sizes and with Chewy’s s&h it’s

Our horses have been prescribed Thyroid L, pergolide and InsulinWise. I wish i could buy all three on Chewy. Thyroid L comes in two sizes and with Chewy’s s&h it’s very easy to order and purchase through them.

Rated 2 out of 5 stars
By Wanda on Sep 21, 2025

Powdered meds are not ideal

This medication has to be mixed with something... In order to det these meds into my already fat horse is to add it to feed! I'd rather not be doing this with

This medication has to be mixed with something... In order to det these meds into my already fat horse is to add it to feed! I'd rather not be doing this with an already overweight horse. Please make a capsule or something that can be hidden in a single treat.

Rated 5 out of 5 stars
By Kim on Nov 21, 2025

Liver support

Thyro-L was recommended by my Vet to help support my horse’s liver & I’ve noticed great improvement in their overall health.

Thyro-L was recommended by my Vet to help support my horse’s liver & I’ve noticed great improvement in their overall health.

Rated 5 out of 5 stars
By Julie on Nov 7, 2025

It works

It is effective but be sure you use it in conjunction with your veterinarian with periodic blood monitoring test to determine thyroid levels

It is effective but be sure you use it in conjunction with your veterinarian with periodic blood monitoring test to determine thyroid levels

Rated 5 out of 5 stars
By Jody on Jan 11, 2026

Convient and effective

It truly helps maintain my horses health issues .

It truly helps maintain my horses health issues .

Rated 5 out of 5 stars
By Janette on Dec 8, 2025

The great fast shipment!

Got a hold of my vet immediately and easy, fast transaction.

Got a hold of my vet immediately and easy, fast transaction.

Rated 1 out of 5 stars
By Nancy on Sep 5, 2025

The special rates are impossible to apply. They are always rejected.

I get an email saying that I have a discount, but then it always does not qualify . No truth in advertising. I do not trust Chewy.

I get an email saying that I have a discount, but then it always does not qualify . No truth in advertising. I do not trust Chewy.

Rated 5 out of 5 stars
By Ester on Jan 9, 2026

Thyro-L

It's helping my mini horses lose weight

It's helping my mini horses lose weight