The ‘539% Hair Growth’ Claim Explained: Absolute vs Relative Results, and What to Expect IRL

The information in this article is for general education only and is not a substitute for personalised medical advice. Always speak to your GP or healthcare provider before making changes to your medication, supplements or treatment plan.

You have seen the headlines: "Revolutionary treatment shows 539% hair growth!" or "New formula delivers up to 400% more hair!" These claims flood social media, inboxes, and beauty press — promising dramatic transformations that feel almost too good to be true. And more often than not, they are.

The most recent example making rounds in the hair loss community is clascoterone 5%, a topical anti-androgen that completed Phase 3 trials for androgenic alopecia. The headline figure — a 539% improvement over placebo — spread rapidly. But when you look at what that number actually measures, the picture is considerably more nuanced. This article breaks down what the mathematics of percentage-based hair growth claims actually mean, using clascoterone as a real-world case study, and sets realistic expectations for what any legitimate treatment can achieve.

The mathematics behind misleading claims

When you see a claim like "539% hair growth improvement," your brain likely imagines someone with thin hair suddenly sprouting five times more strands. The reality is far more complex — and far less impressive than the marketing suggests.

Here is how inflated percentages typically work: companies compare their treatment group against a placebo control, then calculate the relative difference between the two outcomes. The problem arises when the baseline measurements are extremely small, or when the control group actually experiences hair loss during the trial period.

Consider this example: in a 12-month study, the placebo group loses an average of 10 hairs in a measured area, whilst the treatment group gains 5 hairs in the same area. The absolute difference is 15 hairs. However, when calculated as a relative improvement, this becomes a much larger-sounding percentage — and real-world marketing claims often involve even more creative mathematics than this.

Why small baselines create big percentages

The smaller the starting point or comparison group, the easier it becomes to generate impressive-looking percentages. If a treatment increases hair thickness by 0.002mm and the baseline was 0.001mm, that is technically a 200% increase. In absolute terms, however, the change is barely measurable and likely invisible to the naked eye.

This principle applies across every hair growth metric — hair count, thickness, growth rate, and the duration of the anagen phase. Each can produce dramatically different percentage outcomes depending on how the study is designed and how results are calculated.

Absolute vs relative results — what they actually mean

Understanding this distinction is the single most useful tool for evaluating any hair growth treatment claim, from prescription medications to natural serums.

Absolute results

Absolute results tell you the actual, measurable change in concrete terms. For example:

• Hair count increased from 150 to 165 hairs per square centimetre
• Average hair diameter increased from 0.08mm to 0.085mm
• Growth rate increased from 1.2cm to 1.35cm per month
• Shedding decreased from 120 to 85 hairs per day

These numbers are straightforward and honest. They allow you to judge whether an improvement is actually meaningful for your situation.

Relative results

Relative results express the same changes as a percentage compared to a baseline or control group. Using the same examples above:

• Hair count: 10% increase
• Hair diameter: 6.25% increase
• Growth rate: 12.5% increase
• Shedding: 29% decrease

These percentages are accurate — but they are also modest compared to the hundreds of percent you see in marketing materials. The difference is that they use honest baselines and straightforward calculations.

How study design affects reported results

The way a clinical study is designed can dramatically influence the percentages that appear in marketing materials. Three factors deserve particular scrutiny.

Participant selection and baseline conditions

Studies that recruit participants with severe hair loss may show more dramatic percentage improvements than those involving people with mild thinning. If someone has lost 80% of their original hair density, even a modest improvement translates to impressive relative percentages. This is a legitimate criticism of how the clascoterone Phase 3 trial results were communicated — the relative figure tells you very little without knowing the absolute baseline.

Control group considerations

The most misleading percentages often arise when the control group experiences negative outcomes. If the placebo group loses hair whilst the treatment group maintains or slightly improves, the relative calculation can produce inflated improvement percentages. This scenario is particularly common in androgenetic alopecia studies because pattern hair loss naturally progresses over time, so a treatment that simply slows progression can appear dramatically effective against untreated controls.

Measurement timing and selective reporting

Some studies measure results at multiple time points but only report the most favourable outcomes. Peak results might occur at six months with effectiveness declining by 12 months, but marketing materials may only highlight that six-month peak. Legitimate treatments typically show more modest but sustained improvements over time — which is why consistency with a structured scalp routine tends to deliver better long-term results than chasing dramatic short-term claims.

Red flags in hair growth marketing

Recognising these patterns helps you identify claims that deserve extra scrutiny. They do not necessarily mean a product is ineffective — but they signal that you should look for the full data before deciding.

Percentage-only claims

When companies lead with dramatic percentages but provide no absolute measurements, it is often because the absolute results are less impressive. Legitimate studies report both relative and absolute outcomes so you can make a complete evaluation.

Vague measurement descriptions

Claims like "539% hair growth" without specifying what was measured — count, thickness, length, growth rate — are particularly suspicious. Different metrics produce vastly different percentages from the same treatment.

Unrealistic timelines

Hair growth follows the biology of the follicle cycle. Claims of dramatic results within days or weeks contradict basic physiology and should be viewed with scepticism regardless of the brand making them.

Comparison avoidance

Products that avoid comparison to established treatments, or provide no baseline measurements, may be hiding modest efficacy behind inflated language. A brand confident in its results will show you the absolute numbers, not just the relative ones.

What realistic hair growth actually looks like

Real hair growth follows predictable biological patterns. The anagen phase typically lasts two to seven years, with hair growing approximately 1 to 1.5cm per month. Any intervention — prescription or natural — must work within these parameters.

For most people dealing with early-stage thinning or shedding, noticeable improvements typically follow this timeline:

• Weeks 2–4: Reduced daily shedding, improved scalp comfort
• Months 2–3: Existing hair may appear stronger with improved texture
• Months 3–4: New growth becomes visible, particularly along the hairline
• Months 6–8: Density improvements become apparent to others
• Months 8–12: Maximum benefits typically achieved with consistent use

Measuring your own progress honestly

Rather than relying on dramatic before-and-after photos or percentage claims, these objective measures provide more reliable personal feedback:

• Daily shed count — hairs on pillow, in shower drain
• Monthly progress photos taken in consistent lighting
• Hair texture and strength assessment
• Scalp comfort and oil production changes
• Professional trichological assessment every three to six months

These practical measurements often reveal meaningful improvements that would never produce a headline percentage — but represent genuine progress towards healthier hair.

If you are exploring natural alternatives to prescription treatments, applying the same critical lens to ingredient claims is equally important. The same marketing mechanics apply across the category.

The role of professional assessment

Qualified trichologists use standardised measurement techniques that provide objective baselines for tracking progress — scalp photography, hair pull tests, dermoscopy analysis, and detailed examination of growth patterns. Professional assessment also distinguishes between different types of hair loss, each of which responds differently to various treatments. What works for androgenetic alopecia may not be appropriate for telogen effluvium, and a percentage claim designed for one condition tells you nothing useful about the other.

The most effective hair health strategies combine professional oversight with consistent home care. Periodic clinical treatments complemented by daily use of proven ingredients and precision tools consistently outperform either approach used alone.

Building realistic expectations for your hair journey

Effective goal-setting in hair care means identifying specific, measurable outcomes rather than vague aspirations based on marketing claims. Examples of realistic goals:

• Reducing daily shedding by 30% within eight weeks
• Improving hair texture and manageability within six weeks
• Achieving a 15% increase in perceived density within six months
• Maintaining current hair health status through a period of hormonal change or stress

One of the most consistent findings from legitimate hair growth research is that consistent, gentle stimulation outperforms aggressive or sporadic intervention. The scalp responds better to regular, moderate stimulation than to occasional intensive treatments — which is why developing a sustainable daily routine with proven ingredients typically produces better long-term results than chasing the next breakthrough headline.

Frequently asked questions

How can I tell if a hair growth claim is legitimate or just marketing?

Look for studies that report both absolute and relative results, include proper control groups, and measure clinically relevant outcomes over appropriate timeframes. Be wary of claims that only provide percentages without context, promise results within days or weeks, or use vague measurement descriptions. Legitimate treatments typically show modest but consistent improvements over three to six months.

What is a realistic percentage improvement for hair growth treatments?

Most legitimate hair growth treatments produce 10–25% improvements in density, 5–15% increases in hair thickness, and 20–40% reductions in excessive shedding. These percentages may seem modest compared to marketing claims, but they can translate to visibly fuller, healthier-looking hair when sustained consistently over time.

Why do some studies show dramatic results whilst others are more modest?

Study design significantly affects reported results. Research involving participants with severe hair loss, comparing against control groups that lose hair, or measuring at optimal timeframes tends to produce more dramatic percentages. Different measurement techniques — count vs thickness vs growth rate — also naturally produce different percentage outcomes from the same treatment.

How long should I use a hair growth treatment before expecting results?

Due to the natural hair growth cycle, most legitimate treatments require eight to twelve weeks before initial results become apparent, with optimal results typically achieved after six to eight months of consistent use. Any product promising significant results in less than six weeks is likely overstating its capabilities or measuring temporary effects rather than genuine follicle activity.

Can professional treatments like PRP deliver the dramatic results shown in marketing?

Even professional treatments including PRP therapy, prescription medications, and advanced clinical procedures typically produce results in the 20–40% improvement range for density and thickness. They can be more effective than over-the-counter products, but they still work within biological limitations and require realistic expectations to be used and evaluated correctly.