Blume‐Peytavi 2011a.

Methods	This was a randomised, investigator‐blind, active‐controlled trial Setting Departments of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science, Charité‐Universitätsmedizin Berlin, Germany Date of study June 2008 to January 2009 (24‐week duration)
Participants	114 women Mean age (range) = 49.9 years (23 to 75 years) Inclusion criteria > 18 years. Savin grade D3 to D6 female pattern androgenetic alopecia. Hair density ≤ 220 hairs/cm² as measured by TrichoScan. Exclusion criteria Ferriman‐Gallwey score > 6 (scores > 8 indicate excess androgen production). Hypersensitivity to minoxidil or other study ingredients. Local scalp treatments during previous 4 weeks. Systemic treatment 3 months prior to study that could interfere with the study medications. Use of non‐breathable wigs or hair transplants. Participation in another study in previous 4 weeks Chemotherapy, radiation therapy, or laser therapy (on the scalp) within the last 6 months. Pregnancy or desire to become pregnant. Presence of other dermatologic disorders. Severe medical conditions or hair loss diseases. Randomised 113 participants were randomised (minoxidil 5% group = 56, minoxidil 2% group = 57) Withdrawals/losses to follow‐up There were 13/113 (11.5%) withdrawals/losses to follow‐up: 6/56 (10.7%) in the 5% minoxidil group, and 7/57 (12.3%) in the 2% minoxidil group Minoxidil 5% group: 1 participant preference, 1 lost to follow‐up, 3 to adverse events, 1 serious adverse event. Minoxidil 2% group: 4 participant preference, 2 lost to follow‐up, 1 to adverse events. Baseline data The mean Savin hair density score was 4.13 in the minoxidil 5% group, and 3.84 in the minoxidil group 2%. There was a higher proportion of participants with more extensive hair thinning (Savin scores of D5 or D6) in the minoxidil 5% group (N = 19) compared to the minoxidil 2% group (N = 9).
Interventions	Intervention Minoxidil 5% topical foam (MTF) once daily for 24 weeks. Comparator Minoxidil 2% topical solution (MTS) twice daily for 24 weeks.
Outcomes	Assessments (3): at baseline, week 12 and 24 Primary outcomes (as reported) Change from baseline in non‐vellus target area hair count at week 24.¹ Secondary outcomes (as reported) Change in non‐vellus target area hair width. Overall efficacy by global photographic review as assessed by treatment‐blinded evaluators and the subject herself.¹ Adverse events.¹ Participants' assessment of product aesthetics. ¹Denotes outcomes prespecified for this review.
Funding source	Quote (page 1126): "Supported by a medical grant application, Johnson & Johnson Consumer Co Inc."
Declaration of interest	Quote (page 1126): "Dr Blume‐Peytavi is a consultant for Johnson & Johnson Consumer Co Inc. Dr Garcia Bartels was a consultant for Pfizer GmbH Germany until 2008."
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote (page 1127): "24‐week, randomized, investigator initiated and ‐blinded, 2‐arm comparative study" "Participants were randomized (1:1) to treatment with either half a capful of 5% MTF applied once daily or 1 mL of 2% MTS applied twice daily." After e‐mail communication with investigators: the allocation was performed using block randomisation (27 blocks, sequences 4 and 6). Comment: we judged this as adequate.
Allocation concealment (selection bias)	Low risk	The method used to conceal the allocation sequence, that is to determine whether intervention allocations could have been foreseen in advance of, or during, enrolment, was not reported. Comment: There was insufficient information to permit a clear judgement. After e‐mail communication with investigators: in this study, the allocation concealment was "performed using sequentially numbered, sealed, opaque envelopes, and kept by the project manager of the CRC." Comment: we judged this as adequate.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote (page 1128): "investigator‐blinded." "To ensure investigator blinding, participants were instructed to speak in the presence of an investigator only about 'the product' and not to use the terms 'foam' or 'solution' or to mention how many times per day they used the study product. In addition, each participant was instructed to wash their hair before each study visit to avoid providing the study investigators with any indication as to which product they were using." Comment: the blinding of investigators appeared to have been adequate, but the impact of lack of blinding of participants was unclear.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote (page 1127): "investigator‐blinded." Both investigator and participants were the outcomes assessors. Quote (page 1128): "To ensure investigator blinding, participants were instructed to speak in the presence of an investigator only about 'the product' and not to use the terms 'foam' or 'solution' or to mention how many times per day they used the study product. In addition, each participant was instructed to wash their hair before each study visit to avoid providing the study investigators with any indication as to which product they were using." Comment: reasonable attempts were made to blind outcomes assessors (personnel), but it was not possible to blind participants. It's unclear to what extent the lack of blinding had any impact on the participant‐assessed outcomes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The reasons and number of dropouts/withdrawals (13/113 = 11%) from each group were reported and balanced across both active intervention groups. The data analysis was per‐protocol. Comment: although there was per‐protocol analysis, the low percentage of dropouts posed a low risk of bias.
Selective reporting (reporting bias)	Low risk	The protocol for the study was available on clinicaltrials.gov (NCT00958750 and EUCTR2008‐001770‐33‐DE and MINALO3005). The prespecified outcomes and those mentioned in the methods section appeared to have been reported. Comment: we judged this as at a low risk of bias.
Other bias	Unclear risk	There was baseline imbalance, with a higher proportion of participants with more extensive hair thinning in the minoxidil (5%) group. We cannot exclude a potential risk of bias.