PlainVitamins

Thyroid 300

by Priority One Nutritional Supplements · capsule · 120 capsules

  • On the market (NIH)
  • UPC 8 15354 02136 2
  • DSLD label 236920
  • Serving 1 capsule

Thyroid 300 by Priority One Nutritional Supplements lists one ingredient: 300 mg of thyroid per serving of 1 capsule. Its current label entered the NIH Dietary Supplement Label Database on September 25, 2020.

What is in Thyroid 300?

Each row as the label prints it, per serving of 1 capsule. The capsule beside an amount places it among every product in the NIH database that lists the same ingredient: the bar is the middle half of their amounts, the line in it the median, the whiskers the 10th and 90th percentiles; the green tick is the FDA Daily Value and the red dashed tick the adult upper limit (IOM).

Thyroid 300: Supplement Facts rows against the market (DSLD label 236920, January 2026 release)
IngredientAmount% DVAmong products listing it
Thyroid300 mgThyroid in Thyroid 300 against 60 products300 mg per serving; the middle half of products list 31.88 mg to 142.5 mg, the median 100 mg.300 mg

Higher than 92% of 60 products listing thyroid (median 100 mg).

Source: NIH ODS Dietary Supplement Label Database, label 236920 (entered September 25, 2020), version 9.4.0. See the label on DSLD. Amounts are what the maker printed; DSLD does not test products. Daily Values: the FDA's Daily Value page.

Is that a lot?

The rows in the top or bottom tenth of the products that list the same ingredient, and any above the adult upper limit at the most servings a day the directions give:

  • Its 300 mg of thyroid is higher than 92% of the 60 thyroid products that print an amount; 3 list more.

The NIH database records one serving a day from the label's directions; its % Daily Values are for adults and children 4 or more years of age. The directions as printed are further down this page.

The Tolerable Upper Intake Level is the most of a nutrient per day, from food, water and supplements together, that is likely to pose no risk for almost all adults (Institute of Medicine, 2011). It does not apply under medical supervision. This page compares labels; it is not medical advice.

Sources: amounts from the DSLD label; Daily Values from 21 CFR 101.9(c)(8)(iv); adult upper limits from the Institute of Medicine's DRI summary tables (2011). How positions are computed.

Which products have the closest formulas?

6 products list the very same ingredients; the nearest amounts come first.

Source: ingredient lists of every product's current label in DSLD (version 9.4.0); similarity weights each shared ingredient by how rare it is.

What does the label say about taking it?

Quoted from the label as DSLD transcribed it: the maker's words, including any claim about what the product does, which the FDA has not evaluated and PlainVitamins does not endorse.

Directions
Recommendations: Take one (1) capsule daily, or as directed by your physician.
Warnings
Warning: May cause reaction with other thyroid medications.
If heart palpitations, excessive sweating, or hyperthyroidism occur discontinue use. Do not exceed four (4) capsules in a 24 hour period.
Keep out of reach of children.
Allergens and what it does not contain
Contains no preservatives.
Non-GMO
Storage
Keep container tightly closed, store in a cool, dry place.

Source: label statements in DSLD label 236920.

What else is on the label?

Other ingredients: Rice Chelate, Silicon Dioxide, Cellulose, Dicalcium Phosphate, Capsule.

Seals and symbols as the label prints them (the maker's; a certifier's own list confirms a seal): GMP Certified.

How many labels does Thyroid 300 have?

2 labels are on file under this name since September 25, 2020: other sizes, label designs and reformulations. The current one leads this page.

  1. Label 236920 (current) Entered September 25, 2020 · on the market · 120 capsules · UPC 8 15354 02136 2
  2. Label 236919 Entered September 25, 2020 · on the market · 60 capsules · UPC 8 15354 02135 5

Source: DSLD label entry and market events, version 9.4.0 (labels entered through September 25, 2025).

Who makes it?

The label names Priority One Nutritional Supplements, Inc. (distributor). All Priority One Nutritional Supplements products.

Where next?