The Mechanistic Evidence Behind Pycnogenol for Hair and Scalp Health

In this video interview, Franziska Weichmann, PhD, Horphag Research's manager of scientific communications and product development, about a double-blind, randomized, placebo-controlled study examining Pycnogenol's effects on hair health.

The study found a notable 30% increase in hair density at the two-month mark, which declined slightly to 23% by six months, even as scalp microcirculation continued improving throughout the full study period. Weichmann explains that the placebo group showed a similar rise-and-decline pattern, though less pronounced, suggesting the fluctuation may stem from external factors like seasonal or temperature changes rather than the ingredient itself.

Supporting this theory, skin barrier function—measured through transepidermal water loss (TEWL, the amount of water lost through skin)—followed the same trajectory as hair density. Weichmann notes that healthy skin should retain moisture rather than lose it, and the parallel pattern between TEWL and hair density reinforces the idea that outside stressors, not the product's efficacy, may account for the mid-study decline.

On the practical question of how long consumers should wait before expecting results, Weichmann points to the two-month timeframe from the study as a reasonable benchmark, while cautioning that individual factors, including personal stress and lifestyle, can influence outcomes.

She also addresses long-term safety, noting that extended Pycnogenol use has shown no adverse effects, citing a six-year study as one of the longest conducted on the ingredient without reported complaints. Many product formulations recommend starting with a higher dose before tapering to a maintenance level for ongoing use.

The conversation offers formulators and brands insight into both the science behind Pycnogenol's hair and skin benefits and how to set realistic consumer expectations around timing and results.

A transcript of their conversation can be found below.

Nicholas Saraceno: I know that you started getting into it, but the study points to microcirculation. It also points to antioxidant activity as potential contributors to improving hair density. What further research do you think is either planned or needed to confirm the mechanism when it comes to established uses in circulation and skin health?

Franziska Weichmann: I think hair density, hair health, and everything is tightly connected to scalp health, which is basically skin health. We have a lot of data on skin health. As you already mentioned, we have data [pertaining to] microcirculation. We have a lot of data, different studies on microcirculation, but also antioxidants, as you already mentioned. Pycnogenol is a known strong antioxidant ingredient. We also have a lot of studies on inflammation, which is also important for skin health and scalp health. The skin barrier function is very important.

We have very nice findings already regarding the transepidermal water loss, the skin barrier function. We found that in a study where people took Pycnogenol, the researchers took samples of their blood and saw that the gene expression of the loricrin was increased very significantly. Loricrin is an important compound of the outer layer of the skin, which is very important for skin barrier function. This could be one of the explanations why Pycnogenol can help with that.

We have more genetic mechanistic studies that we've done on collagen and hyaluronic acid synthase that were both significantly or both increased, partly significantly after taking Pycnogenol after only a few days. This really also hints to the health of skin after taking Pycnogenol, the skin integrity and the elasticity, and of course, in the scalp, where you have the same thing.

We already have a lot of data on this, which is interesting, but, we wouldn't be called Horphag Research if we wouldn't stop to do research. We always continue to invest in science. We currently have several studies on mechanistic explanations running, not specifically on hair health, actually. But I'm sure there will be another study coming on this as well. It’s really interesting to see how much is invested in understanding what is happening in the body.

Saraceno: At the end of the day, they always talk about the gut-brain axis and other ways that the brain is connected to the rest of the body. And there's certainly truth to that. I know you mentioned Horphag doing a ton of research and, I'm curious, you started to allude to it briefly, but how do you see Pycnogenol fitting alongside some other ingredients when it comes to a potential combination formula? Is there anything you can say about specific interactions or synergies that maybe the manufacturer should be aware of that could be like a good fit for Pycnogenol?

Weichmann: Well, we see a lot of different products that combine different ingredients with Pycnogenol. To see real scientific synergies, we would always have to do a scientific study to really claim the synergy of it. But what we can say is that Pycnogenol is always a good add-on with its antioxidant and anti-inflammatory capacities. It's a good add-on to many different ingredients.

We've never seen that Pycnogenol negatively influences the effect of other ingredients and vice versa, so I think Pycnogenol is just generally helpful for the use of hair and skin health, and many other applications actually.