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Ferric Subsulfate

Generic name: ferric subsulfate topical

Brand names: Monsels, AstrinGyn

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Solution, External:

Astringyn: 259 mg/g (8 g [DSC]) [contains benzalkonium chloride]

Monsels Ferric Subsulfate: (8 mL, 60 mL)


Mechanism of Action

Causes agglutination of surface proteins resulting in hemostasis


Onset of Action

Hemostasis: ≤20 seconds

Use: Labeled Indications

Hemostatic in minor surgical procedures


There are no contraindications in the manufacturer’s labeling.

Dosage and Administration

Dosing: Adult

Hemostasis: Topical: Apply evenly to wound

Dosing: Geriatric

Refer to adult dosing.


Topical: For external use only. Apply to wound using cotton applicator/swab. Avoid contact with eyes.


Store at controlled room temperature. Avoid heat and light.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

Frequency not defined.

Dermatologic: Skin hyperpigmentation (application site)


Concerns related to adverse effects:

  • Hyperpigmentation: May cause heavy pigmentation at application sites, which may result in histologic artifacts (upon rebiopsy) or in radiographic artifacts.

Other warnings/precautions:

  • Appropriate use: For external use only. If inadvertent ocular administration occurs wash eye(s) immediately with large amounts of water or normal saline for approximately 15 to 20 minutes or until no evidence of solution remains.

Monitoring Parameters

Hemostasis at site of application.


Pregnancy Considerations

Ferric subsulfate is used as a hemostatic agent following cervical biopsies (Manca 1997; Tam 2005). May cause vaginal pain if leakage of solution occurs (Tam 2005). A case report also describes use following a miscarriage; fertility was not impaired and a successful pregnancy occurred 7 months later (Disu 2007).

Patient Education

  • Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
  • Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Source: Wolters Kluwer Health. Last updated October 10, 2019.