In 2023, 82% of women taking spironolactone said their acne improved by 24 weeks, versus 63% on placebo. The BMJ SAFA placebo-controlled trial reported the 24-week result in adult women with persistent facial acne. But the earlier clinician-rated bar was much harder to meet.
At 12 weeks, 19% on spironolactone reached investigator-rated success, compared with 6% on placebo. The gap matters if you are staring at jawline bumps in a mirror and wondering why your own sense of change may not match a formal acne score.
At 12 weeks, the clinician score was much stricter
The SAFA trial randomized 410 adult women 1:1 to spironolactone or placebo, alongside standard care. The spironolactone group had 201 women, and the placebo group had 209. Participants were 18 years or older and had moderate or severe persistent facial acne.
The strict 12-week measure was investigator-rated success. In plain English, that meant the investigator saw the acne as clear or almost clear, with at least a 2-grade improvement. The BMJ paper listed 31 of 168 women meeting that bar on spironolactone.
Take an adult woman who has been avoiding close-up photos after 12 weeks of treatment. In the trial’s clinician measure, 31 of 168 women on spironolactone met investigator-rated success. In the placebo group, 9 of 160 did, which the paper reported as 19% versus 6%.
Redness and bumps can lag behind what you notice
Acne on the face is visible, but trial scores try to turn redness, bumps, and overall severity into a fixed result. In SAFA, patient-reported improvement at 24 weeks was 82% with spironolactone, while investigator-rated success at 12 weeks was 19%.
That split fits the way many adults experience breakouts. You may notice fewer tender spots before every pore looks quiet. You may notice makeup sitting differently, less soreness, or fewer new bumps before a formal rating crosses a clear-or-almost-clear threshold.
The EU Clinical Trials Register described the main outcome as the Acne-QoL symptom subscale at 12 weeks. Acne-QoL is an acne-specific quality-of-life questionnaire. It asks about the skin experience, not only whether an investigator can mark the face nearly clear.
Why did the mirror and the rating look different?
The BMJ paper reported both clinician-rated and participant-reported outcomes. By 12 weeks, 122 of 169 women on spironolactone said their acne had improved. In the placebo group, 108 of 159 said the same.
By 24 weeks, the split widened. The self-assessed improvement count was 131 of 160 in the spironolactone group, compared with 81 of 128 in the placebo group. Those figures became 82% and 63% in the published table.
The placebo numbers are also part of the story. At 12 weeks, 68% of women on placebo reported overall improvement, and at 24 weeks, 63% did. Acne trials can capture background care, time, expectation, and natural changes in breakouts, not only the study medicine.
Quality-of-life scores were higher by 24 weeks
The EU Clinical Trials Register lists the Acne-QoL symptom subscale, an acne-specific quality-of-life questionnaire, as the main 12-week endpoint. At 12 weeks, the mean symptom score was 19.2 for spironolactone and 17.8 for placebo.
At 24 weeks, the mean symptom score was 21.2 for spironolactone and 17.4 for placebo. The 12-week analysis included 176 women on spironolactone and 166 on placebo. The 24-week analysis included 163 and 136.
Those are mean scores, not shares of women who improved. That is why the clearest share for the headline is the self-assessed overall improvement result: 131 of 160 women on spironolactone said they improved by 24 weeks.
Every comparison in the trial
The table shows the main comparison a reader can use when placing their own experience next to the trial groups.
| Treatment group | Measure | Share |
|---|---|---|
| Spironolactone | Investigator-rated success at 12 weeks | 19% |
| Placebo | Investigator-rated success at 12 weeks | 6% |
| Spironolactone | Participant-reported overall improvement at 24 weeks | 82% |
| Placebo | Participant-reported overall improvement at 24 weeks | 63% |
What this means for you
If you are taking spironolactone for adult acne, this trial gives useful time points to discuss. At 12 weeks, the strict investigator-rated success number was 19%. At 24 weeks, the patient-reported improvement number was 82%.
Ask your dermatologist or pharmacist how spironolactone fits your skin, other medicines, and acne pattern. Bring notes on tender bumps, new breakouts, redness, and how your skin affects work calls or dates. Do not change a prescription without professional guidance.