---
kind: "section"
citation: "21 C.F.R. § 556.540"
title: "21"
number: "556.540"
heading: "Progesterone."
url: "https://uscodex.org/cfr/21/556.540"
---

# §556.540. Progesterone.

- (a) [Reserved]
- (b) **Residues.** Residues of progesterone are not permitted in excess of the following increments above the concentrations of progesterone naturally present in untreated animals:
  - (1) **Cattle and sheep.**
    - (i) **Muscle—** 5 ppb.
    - (ii) **Liver—** 15 ppb.
    - (iii) **Kidney—** 30 ppb.
    - (iv) **Fat—** 30 ppb.
  - (2) [Reserved]
- (c) **Related conditions of use.** See §§ [522.1940](/cfr/21/522.1940.md) and [529.1940](/cfr/21/529.1940.md) of this chapter.

## Notes

### Authority

Authority: 21 U.S.C. 342, 360b, 371.

### Source

Source: 84 FR 32993, July 11, 2019, unless otherwise noted.