A 28-Day Study on PTT-6 Scalp Activating Mist Reducing Scalp Redness & Soothing Scalp Irritation

Background

Scalp redness, tightness, and irritation are common complaints that people encounter, particularly those with chemically processed hair or sensitised skin. A soothing scalp treatment aims to calm visible irritation and support a more comfortable scalp environment for healthy hair growth. This write-up summarizes a human use study commissioned to evaluate the reduction in scalp redness and soothing efficacy of PTT-6 Scalp Activating Mist over 28 days of continuous use.

Study Design

This was an open-label, single-arm study in which each subject served as their own control (measurements at Day 0 were compared with Day 28, after 28 consecutive days of once-daily use) - there was no separate untreated or placebo control group. 33 adult subjects were enrolled after signing informed consent; 32 completed the study (31 female, 1 male; ages 24–59, mean 47.5 ± 9.6 years; one subject withdrew for reasons unrelated to safety). Subjects had healthy, chemically permed, or dyed-damaged hair and scalp, and were free of scalp disease, active dermatitis, or recent dermatological treatment.

A 1 cm × 1 cm area of scalp was shaved at the temporo-parietal region for standardized imaging at both visits. Two objective measures were recorded on the shaved area: the a* value from an intelligent scalp analyser (a marker of scalp redness, where a lower value indicates less redness) and average hair diameter from a dermatoscope-based hair analysis system. Subjects also completed a 9-item self-assessment questionnaire at Day 28. Adverse events were monitored throughout under a formal safety framework (informed consent, defined adverse-event grading, and a stopping rule), consistent with standard human-use safety practice for cosmetic testing.

Results

After 28 days of use, the scalp a* value decreased significantly from 7.10 ± 1.31 at baseline to 6.11 ± 2.29 (a 13.94% reduction, p = 0.016), indicating significantly less scalp redness. Average hair diameter was essentially unchanged (68.14 µm to 68.29 µm, +0.22%, p = 0.788, not significant).

Table 1. Instrumental results, n = 32. Asterisk denotes 0.01 ≤ p < 0.05 (significant); “ns” denotes p ≥ 0.05 (not significant).

Figure 1. Mean scalp a* value at baseline (D0) vs. after 28 days of use (D28). * p < 0.05.

At Day 28, subject-reported outcomes were uniformly positive: all 32 subjects (100%) agreed or strongly agreed that the product helped soothe their scalp, reduced scalp redness/irritation, improved overall hair quality, improved hair thickness, made hair more voluminous, was easy to apply, and that they would recommend and repurchase the product. No adverse reactions were recorded.

Table 2. Subject self-assessment, D28, n = 32. Self-reported outcomes are subjective and were not independently verified by instrumental measurement.

Practical Relevance

The a* value offers an objective, camera-based proxy for visible scalp redness, complementing what a client reports or what a professional observes in their practice. A significant reduction after 28 days of daily use suggests PTT-6 Scalp Activating Mist may help calm a visibly reactive or irritated scalp with regular use. However, subject-reported improvements in hair thickness and volume were not corroborated by the objective hair-diameter measurement in this study, so any such perceived benefits should be described to clients as reported experience rather than an objectively confirmed change.

Study Considerations

This was an open-label, single-arm (self-controlled) human use study without a separate control or placebo arm and without blinding, so improvements cannot be fully separated from expectation, novelty, or regression-to-the-mean effects - a randomized, controlled, blinded design would be needed to confirm causality. The sample was small (n = 32), predominantly female, drawn from a single population, and followed for only 28 days. The self-assessment questionnaire is inherently subjective, and its 100% agreement rates should be interpreted with the awareness that subjects were aware they were using an active product. This study followed cosmetic consumer-use testing guidelines (T/TDCA 006-2022) rather than a registered clinical trial protocol.

Conclusion

Under the conditions of this 28-day, open-label human use study, PTT-6 Scalp Activating Mist was associated with a statistically significant reduction in scalp redness (a* value, -13.94%, p = 0.016) and uniformly positive subject-reported soothing and satisfaction outcomes, with no adverse reactions recorded. Hair diameter did not change significantly by objective measurement. Together, this supports a scalp-soothing benefit with regular use, while claims regarding hair thickness or volume should rely on subject-reported experience rather than the objective data collected here.

Appendix 1 – Scalp Visualisation

The paired images below show the intelligent scalp analysers’ mapping of scalp redness (red overlay indicates detected redness) at the shaved test site for five representative subjects, comparing baseline (D0) with Day 28 of product use (D28). Reduced red overlay area at D28 visually corresponds to the significant decrease in mean a* value reported in Table 1 and Figure 1.

Appendix 2 – Subject Profile

Profile of all 33 enrolled subjects. Subject 001 withdrew (remark “(5)”: other reasons for dropout, unrelated to safety) and is excluded from the n = 32 efficacy analysis reported above; the remaining 32 subjects completed the full 28-day protocol.

Source: Hangzhou C&K Testing Technic Co., Ltd., Test Report No. CN26070788EN, “PTT-6 Scalp Activating Mist” Human Efficacy Evaluation Test, issued 8 September 2026, commissioned by Calecim Professional.