Clinical study results:
How 77% reported visibly thicker hair after 20 weeks
Hair thinning affects over half of the population by the age of 50 (Alessandrini et al., 2021; Owecka et al., 2024), and many people seek effective solutions for fuller, healthier hair. Although the market is full of products with big promises, relatively few have been evaluated in structured clinical studies.
Summary
A 20-week independent study documented that Acceleroot® Hair Growth Oil can deliver visibly thicker hair and a healthier scalp with no adverse effects. After 20 weeks, participants reported an average of +17.9 hairs/cm², 77% saw thicker-looking hair, 80% experienced less shedding, and 87% reported improved scalp comfort. The results indicate that a natural, botanical product can be a real alternative to traditional treatments.
Contents
- Why hair thinning affects so many
- Study design and methods – How the researchers conducted the investigation
- Results after 20 weeks – Numbers, trends, and experiences
- Real, measurable improvement
- Visible changes over time
- A calmer, healthier scalp - Comparison with well-known alternatives – Minoxidil, finasteride, and natural solutions
- Why a botanical blend? – Ingredients and mechanisms of action
- Month-by-month progress – What you can realistically expect
- Good tolerability and ease of use – No reported adverse effects
- The importance of consistency – Why regular use is key
- Availability and outlook – A new wave in hair care
- Conclusion – A natural, documented, and safe alternative
To help close this gap, Princeton Consumer Research (UK) conducted a 20-week, open-label cosmetic study of a plant-based hair oil. The findings show measurable improvements in hair appearance and scalp comfort, providing early indications that a non-pharmaceutical solution may help in mild to moderate hair thinning.
The study included 34 participants with mild to moderate thinning; 30 completed the entire study period. Participants applied 1 ml of Acceleroot® Hair Growth Oil to the scalp every other day. Effects were assessed at weeks 4, 12, and 20 using HairMetrix® imaging, investigator evaluations, and participant self-reports.
At week 20, HairMetrix® imaging showed a mean increase of +17.9 hairs/cm² versus baseline. Investigators observed visible improvement in 90% of participants, and 70% reported that their hair looked thicker. In addition, 77% were satisfied and would recommend the product, 80% experienced less shedding, and 87% reported better scalp comfort. Importantly, no adverse effects were reported during the study.
Methodology: Why this study matters
This was an independent, open-label cosmetic study without a control group. Multiple assessment methods were used—HairMetrix® imaging, investigator ratings, and participant questionnaires—to reduce subjectivity.
HairMetrix® technology provided objective assessment of hair count and hair width. This was complemented by standardized investigator scales and participant self-assessment, creating a holistic view of both measurable effects and user experience.
What the study showed
Real, measurable improvement
By the end of the 20-week period, participants had on average +17.9 hairs/cm² more than at baseline (p < 0.001). This increase is statistically significant. Although other factors cannot be ruled out (due to the lack of a control group), the trend points to a genuine cosmetic effect.
Visible improvements over time
Hair changes occur gradually. After 4 weeks, 47% felt their hair looked thicker. By week 12 this rose to 70%, and by week 20, 77% said their hair appeared fuller. Reported reduction in shedding followed a similar curve—from 60% at week 4 to 80% at week 20.
A calmer, healthier scalp
Beyond improvements in hair appearance, 83% of participants reported better scalp comfort as early as week 4. By week 20, 87% described their scalp as healthier, calmer, and less irritated or flaky.
Comparison with well-known alternatives
Pharmaceutical treatments remain the gold standard for hair loss but have limitations. Clinical studies with 5% minoxidil solution show increases of 18.6 hairs/cm² after 16 weeks and 20.9 hairs/cm² after 48 weeks (Olsen et al., 2002). Oral finasteride (1 mg daily) increased hair count by ~12.4 hairs/cm² after 24 weeks, 21/cm² after one year, and 27/cm² after two years (Kaufman et al., 1998). However, minoxidil can cause scalp irritation (Nestor et al., 2021), and finasteride may cause systemic side effects, including reduced sexual function (Irwig, 2015).
In contrast, Acceleroot® was well tolerated in this cosmetic study, with no reported adverse effects. While direct comparisons are not possible, the results suggest that a natural, cosmetic alternative can be attractive to those seeking visible improvements without medications.
Why a botanical blend?
Acceleroot® Hair Growth Oil contains 12 botanical oils, vitamins, and nutrients (EuroCosmetics, 2025). The ingredients were selected to act through multiple mechanisms: improved moisture, antioxidant protection, soothing effects, microcirculation, and strengthening of the hair shaft. There is published evidence for some components (e.g., pumpkin seed oil, peppermint oil, amla), while others build on traditional use. It is important to note that only the finished blend was evaluated in this study—not single ingredients.
Good tolerability and easy use
No adverse effects were reported among the 30 participants who completed the study. Unlike some drugs that can cause irritation, this natural oil was described as comfortable and easy to use—making it suitable for regular, long-term application.
What to expect month by month
Weeks 1–4: Adjustment
Early in the study, HairMetrix® showed a small, non-significant decrease of –4.8 hairs/cm² compared to baseline. Some participants also noticed increased shedding, which is a known adjustment reaction—also observed with minoxidil. Still, 47% said their hair looked thicker, and 83% reported better scalp health.
Weeks 5–12: Visible progress
After three months, progress was clear. Net gain in hair density reached +17.0 hairs/cm². 70% felt their hair looked fuller, 77% reported less shedding, and 73% felt their hair was stronger.
Weeks 13–20: Best effect
Towards the end of the study, improvements were well established. Net gain was +17.9 hairs/cm². Investigators observed visible improvement in 90%, while 77% felt hair looked thicker, 80% experienced less shedding, and 87% reported better scalp comfort.
Main takeaway – Consistency is key
Results built gradually, and consistent use appears necessary. Longer studies will be important to assess how durable the effect is over time.
Accessibility makes a difference
As demand for hair care solutions is high globally, it makes sense to offer products that don’t require a prescription or medical supervision. As a cosmetic product, Acceleroot® is easy to access and aligns with the trend toward natural and sustainable beauty solutions. While not always cheaper than pharmaceutical options, it offers a different kind of value: a natural, non-pharmaceutical formulation with documented cosmetic effect.
Outlook
This marks the beginning of a new wave in hair care—where natural, well-designed products are actually tested rigorously. For consumers, this means they no longer have to choose between drugs with side effects and unproven natural products.
A third path is emerging: clinically documented, natural cosmetic solutions. Although this was a single open-label study, it’s an important first step. Further research will be necessary to confirm and build upon the findings.
Conclusion: A cosmetic advance
This 20-week cosmetic study showed that the plant-based Acceleroot® oil was associated with improved hair appearance, increased hair density, and better scalp comfort in people with mild to moderate hair thinning.
After 20 weeks, 77% reported thicker-looking hair, 80% less shedding, and 87% a healthier scalp. No adverse effects were recorded, making this a well-tolerated, natural cosmetic alternative.
The findings provide encouraging indications that natural formulations can play a role in supporting hair appearance—while also underscoring the need for further research.
Noticeable results in just 4 weeks, with further improvements after 12 and 20 weeks
Results from our tests show that Acceleroot® Hair Growth Oil is effective for both men and women.
