---
kind: "section"
citation: "21 C.F.R. § 524.660"
title: "21"
number: "524.660"
heading: "Dimethyl sulfoxide."
url: "https://uscodex.org/cfr/21/524.660"
---

# §524.660. Dimethyl sulfoxide.

- (a) **Specifications.**
  - (1) **Each milliliter (mL) of solution contains 90 percent dimethyl sulfoxide and 10 percent water.**
  - (2) **Each milliliter (mL) of gel product contains 90 percent dimethyl sulfoxide.**
- (b) **Sponsor.** See No. 054771 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Conditions of use in horses and dogs—**
  - (1) **Amount—**
    - (i) **Horses.** Apply topically two to three times daily in an amount not to exceed 100 mL per day. Total duration of therapy should not exceed 30 days.
    - (ii) **Dogs.** Apply topically three to four times daily in an amount not to exceed 20 mL per day. Total duration of therapy should not exceed 14 days.
  - (2) **Indications for use.** To reduce acute swelling due to trauma.
  - (3) **Limitations.** Do not use in horses intended for human consumption. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

## Notes

### Amendments

[79 FR 10967, Feb. 27, 2014]

### Authority

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

### Source

Source: 40 FR 13873, Mar. 27, 1975, unless otherwise noted.

### Amendments

[79 FR 10967, Feb. 27, 2014]