Metformin for the Treatment of Hidradenitis Suppurativa (HS)

Inclusion Criteria: * Age ≥18 years at baseline * A diagnosis of HS for at least 1 year prior to baseline * mild to moderately active disease defined by a HS Physician Global Assessment (HS-PGA) score of 2-3 and the Refined Hurley classification of mild to moderate at baseline * Indication for systemic therapy; i.e. uncontrolled disease under conventional topical therapy. * Able and willing to give written informed consent and to comply with the study requirements Exclusion Criteria: * Pregnant and lactating women * Concomitant diabetes mellitus * Use of antibiotics within 14 days prior to baseline * Use of immunosuppressing/modulating therapies within 28 days prior to baseline * A known allergy to metformin or doxycycline or any of the ingredients metformin or doxycycline