Cannabidiol (CBD) Increases Hair Counts By 246%? Not So Fast.

Article Summary

CBD, a non-psychoactive compound from Cannabis sativa, is being explored for hair regrowth due to its anti-inflammatory, antioxidant, and circulation-boosting properties. Small studies on CBD topicals for androgenic alopecia (AGA) show hair count increases between 55% and 246% over six months. At a glance, this sounds miraculous. But a closer inspection of the evidence paints a different picture. For instance, many participants in these CBD studies were mostly bald, and the investigators tended to choose hair count measurement zones that were also mostly bald. As such, participants saw increases in hair counts of 200%, which is incredible, until you realize that participant went from 2 hairs per square centimeter to 6 hairs (which produces no cosmetic improvement to hair density). Studies have significant limitations: small sample sizes, lack of control groups, and the inclusion of other active ingredients. Additionally, higher concentrations of CBD may harm hair follicles. More research is needed to confirm CBD’s effectiveness for hair regrowth.

Full Article

Cannabidiol (CBD) is a non-psychoactive compound found in the Cannabis sativa plant. It is the second most abundant cannabinoid in Cannabis sativa after tetrahydrocannabinol (THC). As CBD is non-psychoactive, it does not produce the “high” associated with cannabis use. CBD has many therapeutic benefits across several medical conditions, including anti-inflammatory and antioxidant effects, neuroprotective benefits, antitumor properties, and psychological and cognitive benefits. Recently, studies have shown that some of these properties might also benefit hair regrowth. 

In this article, we will examine the benefits of CBD, how it might improve hair regrowth (or not), and whether it is safe and inexpensive to use.

Key Takeaways

• What is it? Cannabidiol (CBD) is a non-psychoactive compound derived from the Cannabis sativa plant. It has many therapeutic properties that might also affect hair regrowth, including anti-inflammatory, antioxidant, and pro-circulatory properties. Furthermore, ex vivo studies have shown that low concentrations can improve hair follicle elongation (although it does not affect cycling or proliferation). However, higher concentrations (1-10 μM) led to negative effects on hair cycling and cell growth.
• Clinical Data. The same research team has conducted two case series evaluating topical CBD products on patients with AGA.
  • Study 1 – Conducted with 35 participants (28 males, 7 females) with AGA. For men, hair counts increased by 74.1% on average. For women, hair counts increased by 55.2% on average. However, the study was limited by a small sample size, lack of control (placebo or comparator), lack of photos, and other ingredients that might also have contributed to positive results.
  • Study 2 – Conducted with 31 participants (15 men and 16 women) with AGA. For men, hair counts increased by 246% on average. For women, hair counts increased by 127% on average. While this appeared to be extremely positive, the example photos of hair regrowth did not show such positive effects. The study was limited by poor photos, a lack of control, and the inclusion of other ingredients that might contribute to hair regrowth.
    • NOTE: In our experience, when studies report large percentage hair count increases without corresponding before-after photos from participants, it’s often an indication of a bias in hair counting methodologies, rather than a reflection of real hair gains. We’re not saying the authors of these CBD studies are engaging in data obfuscation. However, to contextualize these CBD results, a 50%+ increase in terminal hair counts is 5x more than the hair gains reported from FDA-approved finasteride – a drug that produces tangible, cosmetic degrees of hair regrowth for most users. So, we need to ask, if topical CBD is producing 50%+ hair count improvements, why aren’t we also seeing this adequately reflected with quality before-after photos from topical CBD users? We discuss this further in the article.
• Evidence Quality. 32/100 by our metrics.
• Final Thoughts. More robust research studies need to be conducted to determine the efficacy and safety of CBD for hair regrowth. Currently, the lack of evidence quality means that we can not recommend it as a hair regrowth product – at least as a standalone intervention. You may want to try a CBD topical for hair regrowth if you are combining the topical with more proven hair loss treatments, and/or if you have struggled with results from other products and are comfortable trying products that might lack long-term efficacy data.

What Is CBD?

CBD is a compound called a cannabinoid found in the cannabis plant, particularly in hemp. Unlike THC, CBD has no psychoactive properties, but it has many other benefits, including antioxidant, anti-inflammatory, antitumor, neuroprotective, and psychological and cognitive.^[1]Britch, S.C., Babalonis, S., Walsh, S.L. (2021). Cannabidiol: pharmacology and therapeutic targets. Psychopharmacology (Berl). 238(1). 9-28. Available at: https://doi.org/10.1007/s00213-020-05712-8

What Are Cannabinoids?

Cannabinoids are a group of chemical compounds that interact with specific receptors (called cannabinoid receptors) in the body. By interacting with these receptors, cannabinoids can influence various physiological processes.^[2]Richter, S., Quenardelle, V., Rouyer, O., Raul, J.S., Beaujeux, R., Geny, B., Wolff, V. (2018). A systematic review of the complex effects of cannabinoids on cerebral and peripheral circulation in … Continue reading 

There are three main types of cannabinoids:

1. Phytocannabinoids – naturally occurring in the Cannabis sativa plant and include Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). 
2. Endocannabinoids – molecules found inside the body that bind to cannabinoid receptors.
3. Synthetic – artificially produced molecules that are designed to mimic the effects of natural cannabinoids.

Cannabinoids primarily exert their effects through the activation of cannabinoid receptors, CB1 and CB2. CB1 receptors are mostly found in the central nervous system, while CB2 receptors are more common in peripheral tissues and the immune system.^[4]Zou, S., Kumar, U. (2018). Cannabinoid Receptors and the Endocannabinoid System: Signaling and Function in the Central Nervous System. International Journal of Molecular Science. 19(3). 833. … Continue reading However, it should be noted that cannabinoids can also exert their effects through other receptors.

How Does CBD Work?

CBD exerts its therapeutic effects through various mechanisms. Let’s review some of its benefits. Many of these benefits are not explicitly related to hair growth, but we think it is important to take a general overview before exploring the potential role of CBD in hair regrowth in more depth.

Anti-Inflammatory Properties

CBD exhibits significant anti-inflammatory properties, contributing to its therapeutic potential. One pilot randomized, double-blind study in 10 healthy adults was conducted. A single 30 mg dose of water-soluble CBD powder significantly decreased tumor necrosis factor (TNF) levels in lipopolysaccharide-stimulated peripheral blood mononuclear cells (PBMCs) collected 90 minutes after CBD exposure.^[5]Hobbs, J.M., Vazquez, A.R., Remijan, N.D., Trotter, R.E., McMillian, T.V., Freedman, K.E., Wei, Y., Woelful, K.A., Arnold, O.R., Wolfe, L.M., Johnson, S.A., Weir, T.L. (2020). Evaluation of … Continue reading

Antioxidant Properties

CBD has also demonstrated antioxidant activity in experimental models. For instance, one in vitro (in cells) study found that CBD showed 30-50% more antioxidant activity compared to Vitamin E and Vitamin C.^[7]Hampson, A.J., Grimaldi, M., Axelrod, J., Wink, D. (1998). Cannabidiol and Δ9-tetrahydrocannabinol are neuroprotective antioxidants. Proceedings of the National Academy of Sciences of the United … Continue reading This is interesting as Vitamin E and Vitamin C are both used in hair loss products due to their antioxidant properties.

Might Improve Circulation

CBD has been found to modulate blood vessel dilation. One study investigated the effects of CBD on blood vessels, specifically human pulmonary arteries and rat mesenteric arteries. CBD caused significant relaxation of both types of blood vessels, which could improve blood flow.^[8]Baranowska-Kucxko, M., Kozlowska, H., Kloza, M., Sadowska, O., Kozlowski, M., Kusaczuk, M., Kasacka, I., Malinowska, B. (2020). Vasodilatory effects of cannabidiol in human pulmonary and rat small … Continue reading

Anticancer Properties

CBD has been shown to inhibit the growth of various cancer cell types, including breast, lung, colon, and brain cancers.^[9]Heider, C.G., Itenberg, S.A., Rao, J., Ma, H., Wu, X. (2022). Mechanisms of Cannabidiol (CBD) in Cancer Treatment: A Review. Biology. 11(6). 817. Available at: https://doi.org/10.3390/biology11060817

One study found that CBD caused a significant increase in reactive oxygen species (ROS) production in colorectal cancer cells, leading to cell cycle arrest and activation of key proteins such as p53 involved in cell death.^[10]Wang, F., Dezfouli, A.B., Khosravi, M., Sievert, W., Stangl, S., Schwab, M., Wu, Z., Steiger, K., Ma, H., Multhoff, G. (2023). Cannabidiol-induced crosstalk of apoptosis and macroautophagy in … Continue reading

We have examined some of CBD’s properties, but how might this translate to hair regrowth outcomes?

Does CBD Have an Impact on Hair Follicles?

CBD interacts with the endocannabinoid system (ECS), which is crucial for maintaining cellular homeostasis in hair follicles. The ECS includes cannabinoid receptors, such as CB1, and transient receptor potential vanilloid (TRPV) receptors, which are expressed in hair matrix keratinocytes. These keratinocytes contribute to the formation of the hair shaft through a process of proliferation, differentiation, and keratinization.^[11]Toth, B.I., Geczy, T., Griger, Z., Dozsa, A., Seltmann, H., Kovacs, L., Nagy, L., Zouboulis, C.C., Paus, R., Biro, T. (2009). Transient receptor potential vanilloid-1 signaling as a receptor of human … Continue reading

One pilot study was conducted on cultured human hair follicles, treated with 0.1 μM, 1 μM, or 10 μM CBD, or a control. The researchers found that the 0.1 and 1 μM treatments led to improvements in hair follicle elongation. However, this was not significant compared to the control (Figure 4).^[12]Szabo, I.L., Lisztes, E., Beke, G., Toth, K.F., Paus, R., Olah, A., Biro, T. (2020). The phytocannabinoid (-)-cannabidiol operates as a complex, differential modulator of human hair growth: … Continue reading

The highest concentration of 10 μM actually led to a significant decrease in hair follicle length compared to the control, indicating that a higher concentration is not necessarily better.

The researchers also analyzed the effect of CBD concentrations on the hair follicle cycle (Figure 5). They found that although CBD 0.1 μM improved hair follicle elongation, it had no visible effect on the percentage of hair follicles at each stage compared to the control. Furthermore, the 1 μM concentration actually appeared to have a negative effect, increasing the percentage of hair follicles in the regression (catagen) stage. For the 10 μM treatment, the effect was even more pronounced, with a significantly larger percentage of hair follicles in catagen compared to the control.

The researchers also measured the percentage of proliferating cells using ki-67 and the number of dying cells using TUNEL staining. The results showed a dose-dependent decrease in the number of proliferating cells and an increase in the number of dying cells. This indicates a negative effect of CBD on hair follicle cells (Figure 6).

As previously mentioned, CBD activates TRPV channels, which may be the cause of the negative effects. Activation of TRPV4 ion channels has previously been found to induce catagen in human hair follicles, indicating a negative effect of CBD on human hair growth.^[16]Szabo, I.L., Herczeg-Lisztes, E., Szegedi, A., Nemes, B., Paus, R., Biro, T., Szollosi, A.G. (2019). TRPV4 is expressed in human hair follicles and inhibits hair growth in vitro. Journal of … Continue reading

While there might be some positive effects on hair follicles, higher concentrations appear to lead to pronounced negative effects on hair growth and cycling. However, this was an ex vivo study, so let’s take a look at what happens when it is applied to human scalps.

Can CBD Treat Hair Loss?

As far as we can find, there are two case series investigating the effects of topical CBD on hair regrowth in patients with androgenic alopecia. These were conducted by the same research group just two years apart.

Study One

The first study was a case series of 35 participants (28 men and 7 women) not currently using minoxidil or finasteride with a clinical diagnosis of androgenic alopecia (Norwood 3V or 4).^[17]Smith, G.L., Satino, J. (2021). Hair Regrowth with cannabidiol (CBD)-rich hemp extract- a case series. Cannabis. 4(1). 53-59. Available at https://doi.org/10.26828/cannabis/2021.01.003

Each 2 oz jar used for the treatment contained 108 mg of CBD in a lanolin-based paste with emu oil as a carrier. The participants applied a thin layer of the paste over all of the bald or balding areas once daily in the morning for six months. Hair counts of non-vellus hairs were conducted using trichoscopy in a 1 cm2 area at baseline and month 6. They did this by using a clear acrylic mold of each subject’s head, with a one-centimeter square removed at the area with the greatest alopecia. Nonvellus hairs within the square were pulled through the opening with a surgical skin hook and counted using trichoscopy.

Results

The researchers found that for the men, the hair counts in the temporal area increased by 74.1% on average, with the number of hairs increasing from 20.6 at baseline to 33.7. In the vertex area, hair counts increased by 120.1% on average, with the number of hairs increasing from 16.8 at baseline to 32.9 hairs at month 6.

In women, hair counts in the temporal area increased by 55.2%, with the number of hairs increasing from 20.3 at baseline to 20.5 at month 6. In the vertex area, counts increased by 64.9%, with the number of hairs increasing from 18.7 at baseline to 30.7 at month 6.

Furthermore, 33% of participants reported initial increases in hair shedding during month 1; however, these did not continue throughout the rest of the study. Otherwise, no other adverse events were reported.

These results look amazing at first glance, but looking deeper into the data reveals some potential issues. If we took this at face value, it would mean the CBD application would be 5x times more efficacious than finasteride…so why no photos? This study added a table showing the start and 6-month hair counts, along with the percentage increase, and it revealed a problem with using percentage change (Figure 7). As we mentioned above, the researchers chose the areas with the most hair loss for their counts. Using percentage change leads to potential bias issues towards severe cases, with the results overemphasizing small improvements.

This can be seen below, some of the participants experienced very small changes in hair counts (for example, patient 4); however, because their baseline count was so low (6 hairs), the increase of 5 hairs, when turned into a percentage, is an 83.3% increase! Now, we don’t need images to know that that is not a clinically significant increase in hair count, but using the percentage certainly gives the impression that the improvement was more pronounced than it was. If we compare that with patient 13, we can see that they also had a 5-hair increase, but their percentage change was only 13.9% because they started with a higher number of hairs at baseline. We made a video on how companies manipulate data to make it look better than it is (which you can find here if you’re a member).

Another example is patient 28. They started with 4 hairs and ended up with 17, an increase of 13 hairs, which, although we have no photos, we can imagine would not be clinically important—however, that is a huge 325% increase.

Now, we are not saying that the data is being obfuscated here; they gave us the hair counts so we could see for ourselves, but some companies only present percent change, so it’s something that should be kept in mind.

 

Limitations

There are several other limitations associated with the study, including:

• Small sample size (especially for women) 
• The study is uncontrolled, meaning that there is no control group to determine hair cycle seasonality and/or the placebo effect from the treatment, which could account for some of the improvements observed. 
• Some of the participants appeared to have extremely positive results (the highest being a 357.1% change in hair count from Baseline to month 6), but no photos were provided in the paper. Therefore, we cannot see the clinical effects of these so-called improvements.
• The other ingredients (such as emu oil) in this product might also have contributed to any positive effects observed.^[19]Afshar, M., Ghaderi, R., Zardast, M., Delshad, P. (2016). Effects of topical emu oil on burn wounds in the skin of balb/c mice. Dermatology Research and Practice. 1-6. Available at: … Continue reading

Study Two

The second case series conducted by the same author included 31 (15 men and 16 women) participants with AGA.^[20]Smith, G.L., (2023). Hair regrowth with novel hemp extract: a case series. International Journal of Trichology. 15(1). 18-24. Available at: https://doi.org/10.1403/ijt.ijt_34_22 

The topical formulation this time was 1 g of hemp extract (containing CBD), 5 g of menthol, and 600 g of peppermint oil, all infused into a vehicle of 5 g ethanol, 600 g of Emu oil, 14.9 g of hexa fluoroacetone, and 900 ml of dimethicone in each one-oz foam spray dispenser bottle. 

Unlike the previous case series, the researchers tattooed the area of the scalp with the most hair loss to maintain consistent hair counts in a 1 cm2, and photographs were included. The participants were given a 1 oz dispenser and applied a thin layer once every morning to bald areas for 6 months. 

Results

For men, the baseline hair count significantly increased from 6.13 to 21.20 hairs/cm2, showing an average increase of 246%. For women, a significant increase was also observed from 12.69 to 28.75 hairs/cm2, showing an average increase of 127%. This study might have issues similar to those of the previous one. However, they don’t provide any tables of individual patient data, so we can’t know if the high percentage increase was due to actual improvements or small increases from severely balding participants. For the participant perception questionnaires, all participants rated the effects of the product as “happy” or “very happy”.

An independent review of the photographs apparently showed “mild” to “extensive” scalp coverage improvements for all participants. However, the photos tell a slightly different story (Figures 8 and 9). For the male example, there are clear issues. The “before” photo shows wet hair parted to the side to clearly show the bald spot. The “after” photo shows dry, styled hair that has been combed back to cover the bald spot. Because of this, you cannot see any potential new growth in the bald area.

Similar issues can be seen in the female example. In the “before” photo, the hair has been styled to show the full balding area, and in the “after” photo, the hair has been styled back and over the balding spot.

The unfortunate aspect of these images is that they make it look like they are exaggerating results, which is unfortunate because some of the results might actually be decent.

One further issue with this study is that there appears to be a conflict of interest. The company CBDLuxe provided the researcher with a specific CBD topical, which may indicate a conflict of interest as it might affect judgment surrounding the results. However, the paper notes that there is no conflict of interest.

Besides this, the case series suffers from limitations similar to those of the previous study.

Is CBD For Me?

You might want to experiment with CBD if: 

• You are suffering from AGA and want to try a different direction than traditional hair loss products.
• You want to experiment with a natural product to see if it affects hair regrowth.
• You are happy using a product with weak evidence quality.

Otherwise, based on the quality of the evidence, we would not recommend using this ingredient.