Hair Loss Treatments: Evidence for Minoxidil, Finasteride & Laser Therapy | INEE Clinic
Key points
•Choose hair loss treatment by the strength of the evidence, not simply by how new it is.
•A lack of effect and a lack of sufficient evidence are different things.
•Assess the type and extent of hair loss before making a long-term treatment plan.
INEE INSIGHTHair loss · Evidence review
Hair loss treatments:minoxidil, finasteride & laser therapy — the evidence| INEE Clinic
Among the many treatment options, it is evidence—not novelty—that matters.
Hair loss treatment: what can we trust?
Searching for hair loss treatments brings up countless options. From oral and topical medications to lasers, scalp injections, platelet-rich plasma (PRP), supplements and regenerative treatments, the choices continue to grow.
For patients, this has made it harder to know what to choose.
“Which hair loss treatments have actually been shown to work?”
One study offers relatively clear evidence in response to this question: the systematic review and meta-analysis by Adil and Godwin, published in the Journal of the American Academy of Dermatology in 2017. The researchers examined which nonsurgical treatments for male and female androgenetic alopecia had demonstrated effectiveness in reliable clinical trials.[1]
01The key findings
Among the treatments with enough data to be analyzed, minoxidil 2% and 5%, finasteride 1 mg, and low-level light therapy were more effective than placebo or sham treatment in men. In women, minoxidil 2% was shown to be effective. All five analyses found statistically significant differences.[1]
01
Five analyses showing benefit in the 2017 meta-analysis
2017Systematic review · Meta-analysis
4Analyses in men+1Analysis in women
Group
Treatment analyzed
Finding
Men4 analyses
Minoxidil 2%Topical medication
✓Benefit shown
Minoxidil 5%Topical medication
✓Benefit shown
Finasteride 1mgOral medication
✓Benefit shown
Low-level light therapy
✓Benefit shown
Women1 analysis
Minoxidil 2%Topical medication
✓Benefit shown
↗
All five analyses showed statistically significant benefit over placebo or sham treatment.
This table summarizes the scope of the 2017 study. It is neither a list of all treatments available today nor a ranking of treatments.[1]
However, this should not be interpreted as meaning that “treatments outside these five analysis groups do not work.” Many other treatments were excluded because suitable data for analysis were insufficient at the time, rather than because they had been shown to be ineffective.
Understanding this distinction is very important when choosing a hair loss treatment.
02Why established treatments still matter
Minoxidil and finasteride are not new hair loss treatments. Because they have been used for so long, they may even seem unremarkable to patients.
In medicine, however, being well established is not necessarily a disadvantage. Treatments used over many years have been given to many patients, and are more likely to have accumulated research on both their benefits and adverse effects.
In this meta-analysis, minoxidil and finasteride in men, and minoxidil in women, also produced better results than placebo.[1]
Ultimately, the more useful question in hair loss treatment is less “How new is this treatment?” and more “How thoroughly has this treatment been tested?”
03Does laser therapy for hair loss work?
Low-level light therapy was also found to be more effective than sham treatment in this study.[1]
Subsequent studies have repeatedly reported that low-level laser and light therapy may help improve hair density in androgenetic alopecia. A systematic review and meta-analysis published online in 2024 also supported improved hair density after low-level laser and light-emitting diode therapy; most participants in the included studies had androgenetic alopecia.[2]
Care is needed here, too. “It works” and “It works better than medication” are entirely different claims.
The 2017 study assessed whether each treatment was more effective than placebo. It did not directly compare all of minoxidil, finasteride and light therapy to rank them against one another.
02
Showing benefit is different from showing superiority
Question addressed
Does it work?
Individual treatment
↔
Placebo / sham
✓ Benefit shown over placebo or sham
A separate question
Which works better?
Medication
?
Light therapy
The 2017 study did not rank treatments.
Evidence that low-level light therapy works does not establish that it is superior to, or can replace, medication.[1]
It would therefore be inappropriate to extend these findings to claims such as “Hair loss lasers are better than medication” or “Laser therapy alone makes medication unnecessary.”
04“No effect” is different from “not enough evidence yet”
This is the point I consider most important in this paper.
One or two studies on a new hair loss treatment do not immediately establish its effectiveness. Conversely, a lack of large studies does not prove that a treatment is ineffective.
03
Distinguish lack of effect from lack of evidence
A judgment about results
“No effect”
This is a judgment about effectiveness.
A conclusion of no effect also needs research to support it.
≠
A judgment about the available data
“Not enough evidence yet”
There are not enough data to decide.
This is not the same as proving that a treatment does not work.
More important than having a paper is consistent accumulation of evidence.
Treatments not included in the 2017 analysis should not all be classified as ineffective.[1]
For example, later studies reported positive results for platelet-rich plasma and several newer nonsurgical treatments. However, treatment methods, doses and numbers of sessions differ between studies, as does the quality of the evidence.
In a subsequent network meta-analysis comparing treatments, platelet-rich plasma and low-level light therapy were sometimes ranked highly for effectiveness. Even so, the researchers noted that some highly ranked treatments were supported by low-quality evidence.[3]
When considering a new treatment, it is therefore not enough simply to ask, “Are there any published studies?”
We also need to consider how many people were studied, whether there was a control group, whether participants were randomly assigned, whether other studies reproduced the results, and how standardized the treatment methods are.
04
Five questions beyond “Are there studies?”
AssessingEvidence qualityFive questions
01
Study population
How many people were studied?
02
Control group
What was it compared with?
03
Randomization
Were participants randomly assigned?
04
Replication
Did other studies reproduce the results?
05
Standardization
How standardized are the method, dose and number of sessions?
Look beyond the existence of papers to the consistency of the accumulated evidence.
What matters more than the existence of a paper is how consistently the evidence has accumulated.
05Why this judgment matters even more in hair loss
Male and female androgenetic alopecia are usually not conditions that can be treated briefly and then forgotten. Management may be needed for months, years or even longer.
In male pattern hair loss in particular, all the hair does not suddenly disappear one day. Instead, hair growing from affected follicles repeatedly becomes finer and shorter over time.
05
How hair gradually becomes finer and shorter
01
Thick hair
02
Finer hair
03
Finer, shorter hair
Progressive thinning and shortening
Treatment goals to consider together
New hair growth+Preserving existing hair
Slowing the rate of thinning is also an important goal.
A simplified illustration of the process described in the text. It does not represent actual follicle dimensions, a progression timeline or an individual treatment outcome.
The goal of treatment should therefore not be understood solely as “growing lots of new hair.” Preserving the hair that remains for as long as possible, and slowing the rate at which it becomes finer, are also important treatment goals.
For this reason, caution is needed about spending time repeatedly undergoing only treatments whose effectiveness has not been adequately established. Time itself, as well as cost, matters when choosing treatment.
06So, what is the best hair loss treatment?
This is the question patients most want answered, but it is difficult to answer with the name of a single medication or procedure.
Even within male pattern hair loss, someone in their twenties with rapidly progressing recession at the temples may have different treatment goals from someone in their fifties with stable thinning at the crown.
The approach also differs between someone who still has many miniaturized hairs and someone who has already lost a substantial amount of hair. Nor can the same treatment strategy used for men simply be applied to women.
Before deciding on treatment, the first step is therefore less “What should I have?” and more “What type of hair loss do I have, and how far has it progressed?”
06
Assess your hair loss before choosing a treatment
01
Assess the condition
What type of hair loss is present, and how far has it progressed?
Type · Progression · Condition of remaining hair
↓
02
Set the goals
Preserve existing hair and manage future progression
Tailor goals to age, progression pattern and hair condition.
Medication
Light therapy
Supportive care
Hair transplant
Choose the treatments needed for the condition and goals.
Even within the same type of hair loss, goals and approaches differ with age, progression and the condition of the remaining hair.
It is more reasonable to assess the need for medication, light therapy, other supportive treatments or hair transplantation after that evaluation.
07New treatments do not make established ones obsolete
New treatments continue to emerge in the hair loss field. Platelet-rich plasma, microneedling, various injection therapies, stem cell-derived components and exosomes are also being actively studied.
New treatments may well lead to better outcomes. But the arrival of a new treatment does not, by itself, diminish the value of established treatments.
In fact, the newer the treatment, the more closely we should examine its effectiveness compared with established options, whether its results are reproduced in other studies, and its long-term benefits and safety.
The 2017 meta-analysis itself had limitations. Differences between the included studies were substantial, and the authors identified high heterogeneity as a major limitation. This paper should therefore not be interpreted as meaning that a particular treatment produces the same effect in every patient.[1]
08In hair loss treatment, evidence matters more than trends
The message of this study is straightforward.
Some hair loss treatments have demonstrated effectiveness in clinical trials. However, not all treatments are supported by the same level of evidence.
Minoxidil, finasteride and low-level light therapy are representative treatments for androgenetic alopecia with clinical evidence accumulated over a relatively long period. By contrast, some newer approaches are promising but still lack sufficient research.
When starting hair loss treatment, the first question is therefore less “What is the newest treatment available?” and more “Which treatment currently has the strongest evidence for my particular hair loss?”
Hair loss treatment is not a process of trying each fashionable option in turn. It is a process of making a long-term plan to preserve the hair that remains and manage future progression.
References
The main study discussed in the articleAdil A, Godwin M. The effectiveness of treatments for androgenetic alopecia: A systematic review and meta-analysis. Journal of the American Academy of Dermatology. 2017;77(1):136-141.e5. DOI: 10.1016/j.jaad.2017.02.054.
Follow-up review of low-level laser and LED therapyLow-Level Laser and LED Therapy in Alopecia: A Systematic Review and Meta-Analysis. Dermatologic Surgery. 2025;51(2):179–183. Published online October 15, 2024. DOI: 10.1097/DSS.0000000000004442.
Treatment comparisons and assessment of evidence qualityGupta AK, Bamimore MA, Foley KA. Efficacy of non-surgical treatments for androgenetic alopecia in men and women: a systematic review with network meta-analyses, and an assessment of evidence quality. Journal of Dermatological Treatment. 2022;33(1):62–72. DOI: 10.1080/09546634.2020.1749547.
FAQ
QDoes minoxidil actually work?
AYes. In the 2017 meta-analysis, topical minoxidil 2% and 5% in men, and topical minoxidil 2% in women, were more effective than placebo. These findings reflect the scope of that study, rather than a complete list of treatments available today.
QIs finasteride effective?
AFinasteride 1 mg showed a significant benefit over placebo in men with androgenetic alopecia. This finding cannot be applied equally to every type of hair loss or to hair loss in women.
QIs there evidence for laser therapy for hair loss?
ALow-level light therapy was more effective than sham treatment in the 2017 study, and later studies also reported findings supporting improved hair density. This does not mean it is superior to medication or can replace it.
QDoes this mean platelet-rich plasma or regenerative treatments do not work?
ANo. Not being analyzed in this paper means there were insufficient suitable data at the time; it does not mean a treatment was proven ineffective. Further research is accumulating, but the quality of evidence and degree of standardization vary by treatment.
