# Amgen Inc.: Glycerol Phenylbutyrate Oral Liquid to be discontinued

**Score:** 50/100

| Field | Value |
|---|---|
| Manufacturer | Amgen Inc. |
| Drug | Glycerol Phenylbutyrate Oral Liquid |
| Therapeutic category | Inborn Errors |
| Status | To Be Discontinued |
| Stage | Manufacturer discontinuation |
| Presentations affected | 2 |
| Package NDCs | 75987-050-06, 75987-050-07 |
| Manufacturer supply note | Discontinuation in the manufacturing of the drug product |
| Discontinued date | 2026-09-01 |
| First posted | 2026-09-01 |
| Updated | 2026-09-01 |

## Why this score
- The manufacturer is leaving the market.

Source: openFDA drug shortages endpoint (U.S. Food and Drug Administration drug shortage list) (https://dps.fda.gov/drugshortages). Last refreshed: 2026-11-05T09:00:14.778Z.
From the openFDA drug shortages endpoint, which mirrors the FDA drug shortage list and can lag it by days. Availability and recovery notes are the manufacturer's own statements to FDA. Company and product level only. Verify with FDA and the manufacturer before acting.