Hair thinning in women often develops gradually. Instead of a sharply receding hairline, many women first notice a wider part, less volume at the crown, or more visible scalp under bright light. Because these changes can be subtle, researchers need a clear way to describe how advanced the thinning is. One of the most widely used tools for this is the Ludwig scale.
The Ludwig scale was introduced by dermatologist Erich Ludwig in 1977 to classify common patterns of female androgenetic alopecia. It describes hair thinning over the top and crown of the scalp, while the frontal hairline is often relatively preserved [1]. The original scale includes three main stages: Ludwig I, Ludwig II, and Ludwig III. Ludwig I represents mild thinning. At this stage, a woman may notice that her part looks wider or that her hair feels less full than before, but overall coverage is still relatively good. Ludwig II represents moderate thinning, where reduced density becomes more visible and the scalp may show through more clearly. Ludwig III is the most advanced stage, with severe thinning over the crown region [1,2].
In clinical research, Ludwig-style variants are often used to divide these broad stages into more detailed sub-grades, such as I-3 or II-2. These finer categories help researchers describe hair thinning more precisely. This matters because a broad label like “mild” or “moderate” may not be detailed enough to track meaningful change over time. A more specific grade creates a clearer baseline for each participant and allows the study team to evaluate changes more consistently.
This is why RE:YOU selected volunteers with Ludwig grades from I-3 to II-2 for its clinical study. This range represents women with visible, measurable thinning, but not end-stage hair loss. From a study-design perspective, this is an important balance. If participants have only minimal thinning, there may be little room to observe visible improvement. If participants have very advanced thinning, the follicles and scalp environment may be less responsive, making short-term changes harder to measure. Ludwig I-3 to II-2 is a practical middle range where changes in density, scalp coverage, and overall appearance can be evaluated more meaningfully. This range also reflects a common real-world situation. Many women begin looking for hair-density support when they notice their part widening, their ponytail becoming thinner, or their crown losing volume. These concerns usually appear before severe hair loss develops. By studying women in the mild-to-moderate range, RE:YOU designed its trial around the audience most likely to seek early support for visible thinning.
The Ludwig scale also helps make the study population more consistent. Female pattern hair loss can be influenced by genetics, hormones, aging, stress, nutrition, and scalp biology. Because each person’s hair history is different, standardized grading gives researchers a shared language for grouping participants. It also supports a fairer comparison between RE:YOU serums and an on-market minoxidil product, because volunteers begin the study within a defined severity window.
It is important to note that the Ludwig scale is a diagnosis by experts. It is a visual classification tool. A trained evaluator still needs to consider other causes of shedding or thinning, such as thyroid imbalance, iron deficiency, medication-related shedding, stress-related shedding, traction, or inflammatory scalp conditions [3]. However, once female-pattern thinning is identified, the Ludwig scale provides a useful framework for measuring severity and tracking change.
Female pattern hair loss is common, and its prevalence increases with age. Reviews report that many affected women fall into mild or moderate categories rather than the most severe stage [2,4]. This makes early and mid-stage evaluation especially important for both research and product development.
At RE:YOU, we conducted one of the most rigorous clinical trials in the category: 190-person, double-blind, 90-day clinical study, against the field standard Minoxidil, conducted by an independent third party. We selected women in the Ludwig I-3 to II-2 range because this stage is visible and highly relevant to women seeking early support for thinning hair.
After 90 days, RE:YOU showed encouraging results: an 18% greater increase in hair density than topical minoxidil by machine analysis, with 70% of participants experiencing thicker hair*. Expert grading showed a 19% increase in average hair density and a 15% increase in scalp coverage*. Combing and hair counting showed a 58% reduction in shedding, with 79% of participants experiencing reduced shedding*. Survey results also reflected visible daily-life improvements: 90% of users reported thicker hair, 90% experienced less shedding in the shower, 86% saw improved fullness where the serum was applied, and 76% noticed more hair in their part*.
At RE:YOU, we believe you deserve the best care for your hair. That is why we have put our deepest effort into developing, testing, and validating our products. Now, with encouraging results from one of the most rigorous clinical studies in the category, we are proud to introduce the RE:YOU hair care series.
*Based on a double-blinded, 90-day clinical trial against the current gold standard hair growth treatment.
References
[1] Ludwig E. Classification of the types of androgenetic alopecia occurring in the female sex. British Journal of Dermatology. 1977;97(3):247–254. PMID: 921894.
[2] Fabbrocini G, et al. Female pattern hair loss: A clinical, pathophysiologic, and therapeutic review. International Journal of Women’s Dermatology. 2018.
[3] American Academy of Dermatology. Thinning hair and hair loss: Could it be female pattern hair loss?
[4] Chaikittisilpa S, et al. Prevalence of female pattern hair loss in postmenopausal women. Menopause. 2022.
