MedisourceRx
FDA issued a warning letter to MedisourceRx (Los Alamitos, CA, United States) on Dec 12, 2025, citing 21 CFR 310.305 and 21 CFR 201.115. Subject: Compounding Pharmacy, Adulterated Drug Products.
From the letter: “You failed to submit the adverse event report identified in Complaint Log # C25004.”
FDA published a close-out letter on Jul 30, 2026. The findings below are from the original warning letter.
At a glance
What a reviewer notes before reading: findings, citations, the response deadline and what the letter warns of.
- Violations
- 4 findings · 3 issue types
- Cited
- 21 CFR 310.305, 21 CFR 201.115
- Response due
- Fifteen (15) working days of receipt
- FDA asks for
- 4 actions
- Named as possible actions
- Seizure, injunction
- Issued by
- Center for Drug Evaluation and Research
- Published status
- Close-out Jul 30, 2026
AI assisted findings
Model-assisted reading of each issue. Open one to see the FDA text it comes from, and check it against the full letter.
01Complaints & adverse event reportingThe facility failed to submit the adverse event report identified in Complaint Log # C25004.
You failed to submit the adverse event report identified in Complaint Log # C25004.
02Complaints & adverse event reporting · 21 CFR 310.305(b)The facility's procedures for reporting adverse events do not adequately define what constitutes a serious adverse event.
Your documented procedures for reporting adverse events do not adequately define what constitutes a “serious” adverse event (21 CFR 310.305(b)).
03Registration, listing & premarketThe facility does not have FDA-approved applications for its compounded drug products, making them unapproved new drugs.
You do not have any FDA-approved applications on file for drug products that you compound.
04Labeling, claims & marketingThe facility's compounded drug products are misbranded because their labeling lacks adequate directions for use.
Consequently, their labeling fails to bear adequate directions for their intended uses causing them to be misbranded under section 502(f)(1) of the FDCA.
Additional FDA passages
1 extracted findingsSelected FDA passages, not the complete letter.
Failure to Report Adverse Events
What FDA requested
- Notify FDA in writing of specific steps taken to address violations
- Explain each step to prevent recurrence of violations
- Provide copies of related documentation
- Include reasoning and supporting information if products are not in violation
FDA Warning Letter
40 paragraphs · 9 sectionsText as published on FDA.gov, retrieved Sep 8, 2026. Layout added for reading; the wording is FDA’s. View on FDA.gov (opens in a new tab)
1Introduction
2 paragraphs
You registered your facility with the U.S. Food and Drug Administration (FDA) as an outsourcing facility under section 503B of the Federal Food, Drug, and Cosmetic Act (FDCA) [21 U.S.C. § 353b]1 on February 14, 2017, and most recently on December 31, 2024. From May 27, 2025, to June 10, 2025, FDA investigators inspected your facility, MedisourceRx, located at 10525 Humbolt Street, Los Alamitos, CA 90720. During the inspection, the investigators noted that drug products you produced failed to meet the conditions of section 503B of the FDCA necessary for drugs produced by an outsourcing facility to qualify for exemptions from certain provisions of the FDCA.
FDA issued a Form FDA 483 to your facility on June 10, 2024. FDA acknowledges receipt of your facility’s responses, submitted on July 2, 2025, September 5, 2025, and October 10, 2025. Based on this inspection, it appears you produced drugs that violate the FDCA.
2A. Compounded Drug Products under the FDCA
3 paragraphs
Under section 503B(b) of the FDCA, a compounder can register as an outsourcing facility with FDA. Drug products compounded by or under the direct supervision of a licensed pharmacist in an outsourcing facility qualify for exemptions from the drug approval requirements in section 505 of the FDCA [21 U.S.C. § 355(a)], the requirement in section 502(f)(1) of the FDCA [21 U.S.C. § 352(f)(1)] that labeling bear adequate directions for use and the Drug Supply Chain Security Act requirements in section 582 of the FDCA [21 U.S.C. § 360eee-1] if the conditions in section 503B of the FDCA are met.2
An outsourcing facility, which is defined in section 503B(d)(4) of the FDCA [21 U.S.C. § 353b(d)(4)], is a facility at one geographic location or address that — (i) is engaged in the compounding of sterile drugs; (ii) has elected to register as an outsourcing facility; and (iii) complies with all of the requirements of this section. Outsourcing facilities must comply with other applicable provisions of the FDCA, including section 501(a)(2)(B) [21 U.S.C. § 351(a)(2)(B)], regarding current good manufacturing practice (CGMP), and section 501(a)(2)(A) [21 U.S.C. § 351(a)(2)(A)], regarding insanitary conditions. Generally, CGMP requirements for the preparation of drug products are established in Title 21 of the Code of Federal Regulations (CFR) parts 210 and 211.
For a compounded drug product to qualify for the exemptions under section 503B, it must be compounded in an outsourcing facility that is in compliance with the registration and reporting requirements in section 503B(b), including the requirement to submit adverse event reports to FDA “in accordance with the content and format requirements established through guidance or regulation under section 310.305 of title 21, Code of Federal Regulations (or any successor regulations)” (section 503B(a)(1), (b)(5) of the FDCA [21 U.S.C. § 353b(a)(1), (b)(5)]).
3B. Failure to Meet the Conditions of Section 503B
5 paragraphs
During the inspection, the FDA investigators noted that drug products produced by your facility failed to meet the conditions of section 503B. For example, the investigators noted that your facility did not submit adverse event reports to FDA in accordance with the content and format requirements established through guidance or regulation under section 310.305 of title 21, Code of Federal Regulations (or any successor regulations).3 Specifically,
1. You failed to submit the adverse event report identified in Complaint Log # C25004.
2. Your documented procedures for reporting adverse events do not adequately define what constitutes a “serious” adverse event (21 CFR 310.305(b)).
Because your compounded drug products have not met all of the conditions of section 503B, they are not eligible for the exemptions in that section from the FDA approval requirements of section 505, the requirement under section 502(f)(1) that labeling bear adequate directions for use, and the Drug Supply Chain Security Act requirements described in section 582 of the FDCA.
Specific violations are described below.
4C. Violations of the FDCA
0 paragraphs
5Unapproved New Drug Products
1 paragraph
You do not have any FDA-approved applications on file for drug products that you compound.4 Under sections 505(a) and 301(d) of the FDCA [21 U.S.C. §§ 331(d)] a new drug may not be introduced into or delivered for introduction into interstate commerce unless an application approved by FDA under section 505 of the FDCA is in effect for the drug. Marketing of these products, or other applicable products, without an approved application violates these provisions of the FDCA.
6Misbranded Drug Products
1 paragraph
You compound drug products that are intended for conditions not amenable to self-diagnosis and treatment by individuals who are not medical practitioners; therefore, adequate directions for use cannot be written so that a layman can use these products safely for their intended uses. Consequently, their labeling fails to bear adequate directions for their intended uses causing them to be misbranded under section 502(f)(1) of the FDCA.5 The introduction or delivery for introduction into interstate commerce of these products therefore violates section 301(a) of the FDCA. Further, it is also a prohibited act under section 301(k) of the FDCA to do any act with respect to a drug, if such act is done while the drug is held for sale after shipment in interstate commerce and results in the drug being misbranded.
7Failure to Report Adverse Events
1 paragraph
As noted above, your facility failed to submit an adverse event report (section 503B(b)(5) of the FDCA). The failure to report adverse events by an entity that is registered with FDA in accordance with section 503B(b) is a prohibited act under section 301(ccc)(3) of the FDCA [21 U.S.C. § 331(ccc)(3)].
8D. Corrective Actions
4 paragraphs
We have reviewed your facility’s responses to the Form FDA 483.
Some of your corrective actions appear adequate: Your firm retroactively submitted reports of serious, unexpected adverse event reports received prior to FDA’s inspection.
Some of your corrective actions appear deficient: Submitted documented procedures for reporting adverse events do not appear to adequately address the submission of adverse event reports to FDA in accordance with 21 CFR 310.305. For example, the procedures do not clearly define a “serious” adverse event in a manner consistent 21 CFR 310.305(b).
Should you continue to compound and distribute drug products that do not meet the conditions of section 503B, the compounding and distribution of your drugs would be subject to the new drug approval requirement, the requirement to label drug products with adequate directions for use, and the Drug Supply Chain Security Act requirements.
9E. Conclusion
4 paragraphs
The violations cited in this letter are not intended to be an all-inclusive statement of violations at your facility. You are responsible for investigating and determining the causes of any violations and for preventing their recurrence or the occurrence of other violations. It is your responsibility to ensure that your firm complies with all requirements of federal law, including FDA regulations.
You should take prompt action to address any violations. Failure to adequately address any violations may result in legal action without further notice, including, without limitation, seizure and injunction.
Within fifteen (15) working days of receipt of this letter, please notify this office in writing of the specific steps that you have taken to address any violations. Please include an explanation of each step being taken to prevent the recurrence of violations, as well as copies of related documentation. This letter notifies you of our concerns and provides you an opportunity to address them. If you believe your products are not in violation of the FDCA, include your reasoning and any supporting information for our consideration. If you cannot completely address this matter within fifteen (15) working days, state the reason for the delay and the time within which you will do so.
All correspondence should refer to the Warning Letter Number above (# 717970) and include a subject line that clearly identifies the submission as a Response to Warning Letter. If you have questions regarding the contents of this letter, please contact compoundinginspections@fda.hhs.gov.
Citations and trends
Each 21 CFR section, ISO 13485 clause and issue type in this letter, how often it appears across all letters, and its trend by the year FDA issued the letters. 2026 runs to Nov 3, 2026, compared with the same dates last year. Select a row or a bar to see those letters in Letters. As cited in this historical letter, not a statement of current requirements.
Regulations
Issue types
Record details
- Issuing center
- Center for Drug Evaluation and Research
- Issuing office
- Center for Drug Evaluation and Research
- Location
- Los Alamitos, CA, United States
- Letter posted date
- Feb 24, 2026
- Letter issue date
- Dec 12, 2025
- Addressed to
- Director of Quality
- Inspection dates
- May 27, 2025 to Jun 10, 2025
- Response window
- 15 working days after receipt of this letter
Read the source clause
Within fifteen (15) working days of receipt of this letter, please notify this office in writing of the specific steps that you have taken to address any violations.
- Record length
- 1,512 words · 3 recorded redactions
- Published status
- Close-out published Jul 30, 2026
- Original letter
- View on FDA.gov (opens in a new tab)
- Dataset last checked
- Nov 11, 2026 · How this is built
A response window is not a calculated due date. Source excerpts are selected passages. Finding interpretations and categories are model-assisted. Verify the original letter before relying on a finding.