---
kind: "section"
citation: "21 C.F.R. § 520.1248"
title: "21"
number: "520.1248"
heading: "Levothyroxine."
url: "https://uscodex.org/cfr/21/520.1248"
---

# §520.1248. Levothyroxine.

- (a) **Specifications.** Each tablet contains 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 1.0 milligrams (mg) levothyroxine sodium.
- (b) **Sponsors.** See Nos. 059051 and 061690 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Conditions of use—**
  - (1) **Amount.** Administer by mouth as follows:
    - (i) **No.** 061690: 0.1 mg/10 pounds (lb) body weight (0.022 mg/kilogram (kg)) as a single dose every 24 hours or as a divided dose every 12 hours.
    - (ii) **No.** 059051: 0.1 mg/10 lb (0.01 mg/lb, 0.022 mg/kg) body weight twice daily.
  - (2) **Indications for use.** For replacement therapy for diminished thyroid function in dogs.
  - (3) **Limitations.** Federal law restricts this drug to use by or on the order of a licensed veterinarian.

## Notes

### Amendments

[81 FR 22523, Apr. 18, 2016, as amended at 86 FR 57996, Oct. 20, 2021]

### Authority

Authority: 21 U.S.C. 360b.

### Source

Source: 40 FR 13838, Mar. 27, 1975, unless otherwise noted.

### Amendments

[81 FR 22523, Apr. 18, 2016, as amended at 86 FR 57996, Oct. 20, 2021]