This is the 3rd report in our An’du series studying over the counter potions and lotions which claim to help reduce hair loss.
So far we have researched rice water here and rosemary oil here .
Throughout this series we look for proven clinical trials supplying reference to the original document / journal so you can check it out yourself rather than those other well know sources of information AKA TiKTok or Instagram!
Pumpkin Seed Oil - the plant.
Cucurbita Pepo or Cucurbita Maxima or as we know it - the Pumpkin is an annual climber, having seeds which produce a clear yellow to green oil.
Ideally Pumpkin Seed Oil is made from roasting the seeds then cold pressing them, but as always, our modern world has devised cheaper, more efficient and some would argue seedier (pun intended) methods of extraction via solvent or by supercritical carbon dioxide methods. These newer methods are not necessarily healthier as they risk damaging the valuable benefits of the oil especially its antioxidant properties.
Pumpkin Seed Oil is rich in nutrients, such as essential fatty acids including omega 3&6*, β-carotenes, vitamins A, C, E and K, minerals including zinc, magnesium, iron and potassium, lutein, and phytosterols (1) providing both anti-inflammatory and antioxidant properties to the hair and scalp.
It has an intensely nutty flavour and is often used in salad dressings or - and I certainly haven't tried this, it is added to vanilla ice cream for a nutty taste. Cooking with the oil destroys the essential fatty acids so destroying many of its health properties, so if you are going to use the oil as part of your daily diet then use it cold in salads etc.
Pumpkin History and Myth
Pumpkins, native to North and South America are believed to have originated approximately 9,000 years ago, being a staple food to ancient civilizations such as the Aztecs and Native Americans.
How do we know this? well it is thought that the oldest pumpkin seeds have been found in Mexico dating to between 7000-5500 BC and pumpkin seeds have been documented as being used in the Oaxaca Highlands of Mexico over 7,500 years ago.
They are thought to have come to Europe around the late 1400s but no one is quite sure of the exact date.
Historically the oil from pumpkin seeds originated in Eastern Europe namely Austria and Eastern Slovenia with the world’s oldest documented pumpkin seed oil press found in Štajerska (Styria) Slovenia dating back to1750. This area of Austria and Slovenia originally produced much of the world’s pumpkin seed oil with the earliest confirmed record of pumpkin seed oil in Styria being February 18 1697 from the estate of a farmer in Gleinstätten.
Styrian oil – is made by the more traditional cold pressing method of compressing roasted, hull-less pumpkin seeds from a local variety of pumpkin (Cucurbita Pepo) – known as the Styrian Oil Pumpkin and following a quick google I see that the real deal is easily available on line.
Nowadays China is the largest producer of sumpkin Seed oil with over 9 million tonnes of pumpkins annually, India 5 million tonnes of pumpkins and Ukraine comes in third with a ranking of 1 million tonnes annually.
Despite the vegetable originating in the New World, ironically, the common English name used for it has its roots in the 'old' world originating from “peopon,” which means “large melon” in Greek. It then evolved to “pompon” in French and “pumpion” in Britain. The Americans later changed it to “pumpkin,” the name we still use today.
Pumpkin has been known for centuries for its beneficial properties: anti-diabetic, antioxidant, anti-carcinogenic and anti-inflammatory, amongst others.
Its beneficial effects did not go unnoticed and in Austria, pumpkin seed oil has been valued for its healing properties since the 17th century. The Austrian empress Maria Theresia issued a decree in March 1773, in which it was stated:
"This healthy oil is unique and far too precious to be used in tasty meals and should therefore be used as a medicine. It should therefore no longer be used as a culinary delicacy, but only collected and distributed by pharmacists".
With statements like that I don’t doubt that Maria Theresia would have been a great modern-day influencer!
Before we talk about evidence of pumpkin seed oil working as a hair restorer - first I would like to talk a little about hair growth and hair loss.
How does hair grow?
In brief each hair follicle on the scalp produces a hair strand which grows for about 2-6 years (the longer it grows the longer your hair). After growth it goes into its resting phase for several months, then falls out. The cycle then starts all over again.
Androgens are known to help control this cycle; however, it is thought that too much stimulation of the hair follicles by androgens may lead to a shorter growth period, which in turn results in shorter thinner strands of hair and ultimately hair loss.
What do we mean by androgenic alopecia?
Androgenic alopecia (male pattern baldness MPAA and female pattern hair loss or FPAL) is a common form of hair loss in both men and women affecting 30-50% of men by the age of 50 and over 10% of premenopausal women, increasing after the menopause.
In men, there is a well-defined pattern, beginning over both temples then receding to form a characteristic ‘M’ shape. Hair also thins at the top of the head, the combination of both leading to partial or complete baldness. This hair loss can start as early as the teens although is commoner as you get older.
In females the hair loss pattern is different, the hair becomes thinner at the top of the head and the middle parting widens. The hairline does not typically recede, and it very rarely leads to total baldness as it can in men. Usually in females this hair loss starts at the time of the menopause. As with male pattern hair loss, androgens play a role in female pattern hair loss, but there are other less clearly defined factors involved.
The causes of androgenic alopecia?
The causes of male and female pattern hair loss are thought to be a combination of both genetic and environmental factors - although there is little evidence as to what these environmental factors are. We do know that a genetic variant on the AR (Androgen Receptor) gene does result in the androgen receptors being more easily stimulated, so exhausting them ultimately leading to miniaturisation of the hair follicle and subsequent hair loss.
Figure 1: diagram showing normal hair growth
Figure 2: diagram showing how hair loss occurs in people with male or female pattern baldness (mutation of the AR gene)
And what about other types of hair loss?
Other types of hair loss include stress, traction alopecia (hair style pulling on your hair follicles), medications, overall nutritional status, some health problems for example thyroid disorders , depression, auto-immune disorders.
Pumpkin seed oil is thought to work by blocking the conversion of testosterone to DHT. Less DHT results in a reduction in overstimulation of the hair follicles so reducing the chance of hair loss.
Pumpkin seed oil - the hair restorer
This is where we really want information, and while there are some trials - listed below - it has to be said that they are all relatively small making it difficult to interpret. The 2014 a Pumpkin seed oil trial involved 76 participants. Compare this to the Wegovy trial (the weight loss drug that has been in the news recently) which, made by Novo Nordisk, involved 17,000 participants or the even bigger Million Women Study done at Oxford on hormone replacement therapy (HRT) looking at side effects of HRT. A small trial doesn't necessarily mean that something doesn't work, just that you haven't got the big numbers to prove it. If the big drug companies don't see a profit at the end with something so generic as Pumpkin seed oil, then they are not going to put the money into doing a trial on it. So, funding for such trials is often difficult to find.
The 2014 trial (2) mentioned above, comparing pumpkin seed oil to placebo did clinically demonstrate an improvement in hair growth with those using the pumpkin seed oil. As mentioned, the study was relatively small with 76 participants all of whom were males suffering from Androgenic Alopecia.
Like Rosemary oil, pumpkin seed oil's mode of action is hormonal, inhibiting the enzyme 5-alpha- reductase which converts testosterone to Dihydrotestosterone (DHT). The overall reduction in DHT causes less stimulation and so less overall exhaustion on the hair follicle - especially in those in those people with the AR gene who are prone to overstimulation of the hair follicle.
Also, compared to hair loss treatments such as prescription only finasteride and minoxidil, Pumpkin Seed Oil has fewer side effects which in my mind is a big plus.
Promisingly a similar study was done on females in 2021 trial (3) comparing pumpkin seed oil with minoxidil 5% foam in females with female pattern hair loss (FPHL). This showed evidence of a potential role of pumpkin seed oil in the treatment of FPHL. Both the above trails involved oral pumpkin seed oil, not its topical use.
So, what about the topical use of pumpkin seed oil? In 2019 some researchers showed encouraging results of topical pumpkin seed oil being used to help regenerate hair follicles – trial (4) . This trial used mice comparing topical pumpkin seed oil to topical minoxidil, testosterone and a combination of the above applied for 6 days a week for a total of 3 weeks. Topical pumpkin seed oil was shown to increase the hair growth in mice which was confirmed with microscope findings.
Pumpkin seed oil can also help with the overall appearance of your hair, it has superb moisturising properties - deeply nourishing the hair adding shine without weighing down the hair strand along with its generic qualities of being rich in vitamins, minerals, antioxidants and anti-inflammatory properties – all of which help support a healthy scalp and hair growth.
Conclusion
So, in conclusion, trials have shown in both men and women that oral supplements of pumpkin seed oil do improve hair growth but only where the hair loss is due to male or female pattern alopecia areata, positive effects showing after 3 months while topical application of the oil helps hair regrowth in mice but I have yet to find an equivalent trial on humans.
As with rosemary oil, firstly exclude other underlying causes of your hair loss, and, if your hair loss has been confirmed to be MPAA or FPAL (hormonally mediated hair loss) then oral supplements of Pumpkin Seed Oil have been shown to help, while topical application in theory helps - but proven in mice only. No trials have shown that eating more pumpkin seeds helps hair regrowth – but that’s because no trial has been done as far as I can see!
And, when your shampoo claims to help your hair growth by containing pumpkin seed oil – remember the science is behind it for oral supplements, and topical oil on mice but no trials have been done with pumpkin seed oil added to shampoo.
The dose of pumpkin seed oil taken orally in the trials was 400 mg daily for 6 months, so it would be reasonable to say that the same amount should be taken if you were trying it at home to help restore hair growth.
While side effects of oral pumpkin seed oil are minimal it can cause some stomach aches as well as lowering your blood pressure in some people – so care should be taken if also taking blood pressure lowering tablets.
When applying topically, advice is given to apply at night, rubbing gently into the roots, use an old pillowcase to avoid oil stains and shampoo off in the morning. Apply every time you wash your hair. Advice is to maintain this regimen for 3-6 months for maximum benefit – this must be anecdotal advice as I can find no clinically proven trial on humans following this regimen. Of course, the wonderful antioxidant, anti-inflammatory effects as well as moisturising properties of pumpkin seed oil topically will help your hair look strong and smooth even without pumpkin seed oil’s hormonal effects.
One note of caution if you are going to try the topical oil method, care should be taken if your hair is prone to dandruff as oils can provide an environment for yeast to thrive so aggravating any pre-existing dandruff.
And finally, thank you for reading the above and if you have found any other relevant trial or any anecdotal evidence, please do leave a message below – we would love to know.
References:
- Batool, Maria, et al. “Nutritional Value, Phytochemical Potential, and Therapeutic Benefits of Pumpkin (Cucurbita Sp.).” Plants, vol. 11, no. 11, 24 May 2022, p. 1394, https://doi.org/10.3390/plants11111394. Accessed 8 June 2022.
- https://onlinelibrary.wiley.com/doi/10.1155/2014/549721
- https://onlinelibrary.wiley.com/doi/abs/10.1111/jocd.13976
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6823528/
* The fatty acid profile is broken down to 40-62% Linoleic acid, 18-38% Oleic acid, 8-16% Palmitic acid and 3-7% Stearic acid.
The above is for information only and not meant to be a substitute for medical advice. Always speak to a trained physician if you require medical advice.