Gastrointestinal Side Effects of Low-Dose Oral Minoxidil in Patients with Alopecia: An Underrecognized Association.
- 1Dermatology Department, University Hospital, Unidade Local de Saúde (ULS) Coimbra. Faculdade de Medicina da Universidade de Coimbra, Portugal.
- 2Cardiology Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, CIBERCV. Universidad Europea. Universidad Complutense. Madrid, Spain.
- 3Centro de Dermatologia de Lisboa, Portugal.
Abstract
Introduction
Low-dose oral minoxidil (LDOM) has become an increasingly used therapy for alopecia. While dose-dependent hypertrichosis is the most common side effect, gastrointestinal (GI) adverse effects are plausible due to smooth muscle relaxation, but they have not been systematically reported in clinical studies.Objectives
To investigate the frequency and characteristics of GI adverse effects in patients treated with LDOM for alopecia.Methods
We conducted a prospective observational study at a trichology unit including patients attending their second consultation after initiating oral minoxidil between May and August 2025. A structured questionnaire assessed new GI symptoms, temporal relationship with treatment, and concomitant medication use.Results
Among 302 patients (218 females, 84 males; mean age 46 years), 22 (7.3%) reported new GI symptoms. The most frequent symptoms were flatulence (N=18), heartburn (N=13), abdominal distension (N=12), abdominal pain (N=10), and aerophagia (N=7). Symptoms resolved after discontinuation in 15 of 16 cases and recurred after reintroduction in 14 of 15. A dose-response association was observed (mean dose in patients with GI symptoms 2.7 ± 1.6 mg vs. 1.3 ± 1.2 mg in those without, P=0.01). GI side effects were more common in males (15.5%) than in females (4.1%, P<0.001) and in patients treated with concomitant vasodilators (25.6% vs. 4.6%, P<0.001).Conclusions
GI complaints, particularly aerophagia, abdominal pain or distension, and flatulence, appear to be underrecognized adverse effects of LDOM. Although generally mild, these symptoms may affect adherence and quality of life. Clinicians should inquire about GI complaints, especially in male patients receiving higher doses or concomitant vasodilators.
Related
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BibTeX
@article{soares2026gastrointestinal,
title = {{Gastrointestinal Side Effects of Low-Dose Oral Minoxidil in Patients with Alopecia: An Underrecognized Association.}},
author = {João Soares and Manuel Martínez-Sellés and Rui Oliveira Soares},
journal = {Dermatology practical \& conceptual},
year = {2026},
month = jul,
doi = {10.5826/dpc.1603a7007},
url = {https://europepmc.org/article/MED/42858418},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Gastrointestinal Side Effects of Low-Dose Oral Minoxidil in Patients with Alopecia: An Underrecognized Association.
AU - João Soares
AU - Manuel Martínez-Sellés
AU - Rui Oliveira Soares
PY - 2026
DA - 2026/07/31
JO - Dermatology practical & conceptual
DO - 10.5826/dpc.1603a7007
UR - https://europepmc.org/article/MED/42858418
AB - Introduction Low-dose oral minoxidil (LDOM) has become an increasingly used therapy for alopecia. While dose-dependent hypertrichosis is the most common side effect, gastrointestinal (GI) adverse effects are plausible due to smooth muscle relaxation, but they have not been systematically reported in clinical studies.Objectives To investigate the frequency and characteristics of GI adverse effects in patients treated with LDOM for alopecia.Methods We conducted a prospective observational study at a trichology unit including patients attending their second consultation after initiating oral minoxidil between May and August 2025. A structured questionnaire assessed new GI symptoms, temporal relationship with treatment, and concomitant medication use.Results Among 302 patients (218 females, 84 males; mean age 46 years), 22 (7.3%) reported new GI symptoms. The most frequent symptoms were flatulence (N=18), heartburn (N=13), abdominal distension (N=12), abdominal pain (N=10), and aerophagia (N=7). Symptoms resolved after discontinuation in 15 of 16 cases and recurred after reintroduction in 14 of 15. A dose-response association was observed (mean dose in patients with GI symptoms 2.7 ± 1.6 mg vs. 1.3 ± 1.2 mg in those without, P=0.01). GI side effects were more common in males (15.5%) than in females (4.1%, P<0.001) and in patients treated with concomitant vasodilators (25.6% vs. 4.6%, P<0.001).Conclusions GI complaints, particularly aerophagia, abdominal pain or distension, and flatulence, appear to be underrecognized adverse effects of LDOM. Although generally mild, these symptoms may affect adherence and quality of life. Clinicians should inquire about GI complaints, especially in male patients receiving higher doses or concomitant vasodilators.
SN - 2160-9381
ER -