By week 12 in 2016 FDA acne trials, people on vehicle gel had inflamed lesions fall 49% and 47%. The FDA medical review reported those two vehicle-arm drops for dapsone gel trials, alongside active-gel results.
But the comparison side was not still. The same FDA table reported 38% and 40% drops in non-inflammatory lesions on vehicle gel. For anyone checking jawline acne on video calls, that can make a before-and-after photo harder to read.
Inflamed spots fell 49% in one comparison group
The 2016 FDA review said lesion counts were done at screening, day 1, and weeks 1, 2, 4, 8 and 12, with early exit visits included. That schedule measured visible acne repeatedly, not only at the start and finish.
Trial 006 listed 1,044 people in the active arm and 1,058 in the vehicle arm. Trial 007 listed 1,118 and 1,120. The active gel was statistically superior to vehicle gel at week 12, according to the FDA review.
Take an adult who starts a trial with inflamed jawline bumps and closed-looking clogged spots. If her skin follows the vehicle-arm pattern, her red bumps could look reduced before the active ingredient's extra advantage is counted.
Week 12 counted both red spots and clogged pores
The FDA separated inflammatory lesions from non-inflammatory lesions. In plain English, inflammatory lesions are red, swollen-looking acne spots. Non-inflammatory lesions are clogged pores such as comedones. Both types changed in the vehicle groups by week 12.
The same review said efficacy was assessed at week 12 by at least a 2-point reduction in Investigator's Global Assessment and a score of 0 or 1. It also counted absolute and percent changes in non-inflammatory and inflammatory lesions.
Why can the inactive side move so much?
The FDA documents do not give one single reason for the vehicle-arm changes. They report the comparison. A vehicle arm means people used the base gel or cream for the trial comparison, without the tested active ingredient.
The narrow reading is this: in these FDA acne tables, vehicle groups improved by week 12. The numbers do not prove why one person's acne changed, and they do not make a vehicle product a treatment plan.
Another FDA label counted double-digit lesion drops
A 2022 FDA label for clascoterone cream reported vehicle-cream results in two acne trials. In Trial 1, the vehicle group had 350 people. In Trial 2, the vehicle group had 362 people. The active groups had 342 and 367 people, so each comparison arm was similar in size.
By week 12, the label reported mean absolute reductions of 13.0 and 10.8 non-inflammatory lesions in the two vehicle-cream arms. For inflammatory lesions, the vehicle-cream reductions were 15.4 and 12.6 lesions. The label measured subjects aged 12 years and older in aggregate, but the example here stays with an adult because Crowley Star writes for adults managing acne now.
Every vehicle-arm result from the FDA tables
These are the comparison-side numbers from the two FDA sources, using rounded whole percentages for the 2016 percentage changes and the label's lesion counts for 2022.
| FDA source and trial | Lesion type in vehicle arm | Week 12 result |
|---|---|---|
| 2016 FDA dapsone review, Trial 006 | Inflammatory lesions | 49% reduction |
| 2016 FDA dapsone review, Trial 007 | Inflammatory lesions | 47% reduction |
| 2016 FDA dapsone review, Trial 006 | Non-inflammatory lesions | 38% reduction |
| 2016 FDA dapsone review, Trial 007 | Non-inflammatory lesions | 40% reduction |
| 2022 FDA clascoterone label, Trial 1 | Inflammatory lesions | 15.4 fewer lesions |
| 2022 FDA clascoterone label, Trial 2 | Inflammatory lesions | 12.6 fewer lesions |
| 2022 FDA clascoterone label, Trial 1 | Non-inflammatory lesions | 13.0 fewer lesions |
| 2022 FDA clascoterone label, Trial 2 | Non-inflammatory lesions | 10.8 fewer lesions |
What this means for you
If your acne looks better after several weeks on a cream, avoid judging the whole change from one selfie. Lighting, camera distance, picking, timing and the base product can all affect what you see. Ask a dermatologist or pharmacist how to use acne treatments and how long to track them.
If your acne is painful, scarring, spreading to your chest or back, or affecting dates, work or video calls, bring photos from the same lighting and angle. That makes the conversation more useful than a single mirror check on a stressful morning.