You can find juniper trees in Japan, Europe and North Africa; they grow to between 6 and 25 feet tall, and have stiff, needle-like blue and green leaves. You can see a picture of the tree and its berries to the left.
In Northern European countries, juniper berries are used to impart a strong and sharp flavour to meat dishes. In Turkey, juniper berries are ground down into a traditional fruit paste called pekmez.
For centuries juniper berries have been used to flavour gin; the name ‘juniper’ derives from the word ‘genievre,’ which is French for gin. Meanwhile the Ancient Greeks, who seem to have had a crystal orb which gave them the knowledge on every plant confirmed to be healthy by the 20th century whether it was honey or aloe vera, used juniper berries in Olympic events because of their belief that they increased physical stamina.
America isn’t missing out on the juniper berry fun either; in fact, the opposite is true. Juniper berries are an invasive species in Arizona because of years of cattle grazing. The native grasses are being killed as the juniper berry moves in. People are despairing at the ever-increasing invasion of berries and wishing that they could at least grab a handful and eat them in a bowl like blueberries (you can’t).
There are two key types of juniper oil. There’s the essential oil distilled from the tree’s needles, twigs, wood and berries. Then there’s the juniper berry oil, which is solely extracted from the berry. The berry oil is what we’re interested in. This acne treatment is an essential oil, like tea tree oil or thyme oil; it’s not a fat-based carrier oil like grapeseed oil or olive oil.
Why do we care about juniper berry oil? Because of the following study from 2005:
A promising study directly on acne
A gang of scientists set out to analyse the effect of micro-particles containing juniper berry oil on levels of acne vulgaris in humans. The oil was tested against p.acnes bacteria and acne itself, and two forms were tested: oil encapsulated within micro-particles and isolated juniper oil.
The juniper oil formation had strong activity against both p.acnes bacteria and acne itself. When diluted with carrier oils, juniper berry oil still had a strong effect.
Testing the juniper berry oil wasn’t actually the purpose of this study. The real goal was to analyse the potency of micro particles for delivering any topical treatment; the juniper berry oil was simply the one that they chose to test.
That suggests that the scientists already knew that juniper berry oil was an effective acne treatment, as though it was common knowledge in dermatology behind the scenes. Otherwise, the scientists would have chosen a proven acne treatment, like grapeseed oil or sea buckthorn oil.
Overall, this is a very vague study, but it clearly demonstrates that juniper berry oil can lower acne.
It came out of nowhere; there’s little previous evidence directly on acne. Looking through the history books, there are a few hints at juniper oil’s potential. For example, Turkish folk medicine used the juniper berry for wound healing – that could translate to faster pimple healing. The Native Americans of the south-eastern USA used it to cleanse and heal the body and keep away infection. They also claimed that the juniper berry is “an excellent survival food”, and lived off it during starvation, possibly when the buffalo all went on holiday to Hawaii; maybe that means that the oil is loaded with acne nutrients.
However most of the old tales and folklore remedies are deep in the realm of superstition, not skincare. The juniper berry is riddled with old wives tales.
During the biblical era, the juniper berry was used to banish evil spirits. By the Medieval times, this had progressed to warding off witches. Bundles of juniper berries were hung over doors to prevent witches from entering the house. Many planted a juniper bush by the front door; the theory was that a witch could only breach the magical barrier if they correctly counted the number of needles on the plant.
There’s no use for acne in there unless witches are the real cause. Tales like this surface repeatedly throughout history; burning juniper wood was said to deter demons as well.
It’s clear that our only avenue of research left is the hard data from scientific studies…
The studies on juniper oil are all over the place
First up we have a couple of other studies which analysed the antibacterial properties in a broad way, rather than on p.acnes bacteria specifically.
This 2005 study analysed the antimicrobial activity of juniper berry essential oil. The oil was tested against 16 different bacterial strains, seven yeast-like fungi and three yeasts. Juniper oil showed strong antibacterial activity, against both gram-positive and gram negative bacterial species.
That’s promising because p.acnes, which wasn’t tested, is gram positive. Juniper berry oil could clearly kill a wide variety of bacteria as well. There was a strong fungicide activity against yeasts, with the strongest being against candida. The takeaway: juniper berry essential oil has potent antimicrobial properties.
This study, however, was far more mixed. 3 different juniper berry oils from 3 different species of the plant were applied to antibiotic resistant microorganisms, including bacteria and fungi. Only one of the juniper oil varieties demonstrated significant antimicrobial properties.
No component of the oils such as the alpha pinene was stronger than the whole oil. There are over 70 species of the juniper plant worldwide; it’s possible that the positive study had bad luck and selected one of the only effective ones. Alternatively, it could be that this study selected three of the most ineffective ones.
Next up are the anti-inflammatory properties of juniper berry oil, if they exist. This study found that they do in some species; 5 species of juniper oil were tested including Juniperus excelsa, Juniperus communis, Juniperus foetidissima, Juniperus oxycedrus and Juniperus phoenicea. Both wound healing and anti-inflammatory properties were tested.
The J. oxycedrus and J. phoenicea both demonstrated “remarkable wound healing and anti-inflammatory activities”. These are two of the less researched species of juniper berry; the most common variety is Juniperus communis.
The other two species had no significant effect. A mixed study overall, because with the 70 species worldwide, it would be a challenge to identify which truly work on acne.
This study on inflammation was a disaster. Neutrophils are immune system chemicals which release bursts of free radicals as part of their function, with the intention of breaking down old and dying tissue to make way for a replacement. Excessive neutrophil accumulation in the skin can 1) inflame that skin, and 2) deplete antioxidants there.
The study analysed the effect of juniper oil on neutrophils and methylperoxidase (MPO) levels. The oils of geranium, lavender, tea tree, and eucalyptus were also tested.
The good news for acne: geranium oil inhibited the skin inflammation associated with neutrophil accumulation excellently.
The bad news – juniper oil was the only oil that didn’t. It was left in the dust by all the other essential oils. The tea tree, lavender and eucalyptus oils reduced inflammation less effectively than geranium oil, but still strongly.
Finally, we have the relationship with antioxidant levels, which is far more promising. This study analysed extracts from the berries of six different species of the juniper plant. J. oxycedrus, J. Sabinal, J. excelsa, and J. phoenicea all showed strong antioxidant activities against the oxidation of linoleic acid.
That’s very promising for acne, because linoleic acid is a natural ingredient of human sebum; you don’t want it to oxidise and spread free radicals across your face. The four species of juniper were reportedly rich enough in antioxidants to potentially be used as preservatives to extend the shelf life of raw and processed foods.
This study analysed 5 different Juniperus species from Turkey. All had high levels of polyphenol antioxidants and overall antioxidants.
This study brought up the specific antioxidant compounds found in juniper berries. Two new compounds were identified, called gossypetin-hexoside-pentoside and gossypetin-hexoside. Previously identified antioxidants in the juniper berry included many polyphenols, flavonoids, and bioflavonoids. It’s clear that juniper oil has plenty of antioxidants and a great variety of them as well.
How does juniper berry oil fare for acne overall? For bacteria, the news is mildly positive. For inflammation, the jury is out. For antioxidants, this topical treatment is promising.
The active components of juniper berry oil
Like tea tree oil or rosemary extract, the essential oil of the juniper berry is made up of several dominant components. The oil tested in one study was found to consist of alpha-pinene (29.17%), beta-pinene (17.84%), sabinene (13.55%), limonene (5.52%), and mircene (0.33%). P-cymene, camphene, and alpha and beta phellandrene are also minor components of juniper berry oil.
Are any of these active compounds known to affect acne?
ALPHA PINENE – a diterpene antioxidant also found in tea tree oil and rosemary extract. It’s the most promising compound here; two studies have been conducted directly on p.acnes bacteria.
This study analysed the alpha pinene extracted from tea tree oil, alongside two of its other compounds called terpineol-4-ol and alpha terpineol. All three had strong activity against p.acnes bacteria; alpha pinene was branded as a “broad spectrum antibiotic”. It happens to be the main active compound in juniper berry oil, with minor variation based on the specific species.
This study found that guava oil had strong activity against p.acnes bacteria (watch out for an article on it sometime); the main active component of guava oil is alpha pinene. This study on mice found that alpha pinene could inhibit a variety of pro-inflammatory chemicals such as interleukin-6 (IL6), cyclooxygenase-2, and TNF-a.
It also inhibited the NF-kappaB transcriptor, the master regulator of many pro-inflammatory chemicals behind acne. Overall, alpha pinene is an interesting topical compound for acne.
BETA PINENE – beta pinene is a lot less researched than its older brother. This study found that alpha pinene was only mildly active at reducing inflammation, while beta pinene was completely inactive.
However, it seems to have decent antibacterial properties; this study found that when combined, alpha pinene and beta-pinene have a synergistic effect against bacteria. Juniper berry oil contains them both side by side. Both a-pinene and b-pinene killed 100% of candida yeasts within 60 minutes of application.
The powers may extend to p.acnes bacteria, or they may not. This study compared the antibacterial powers of three compounds from rosemary extract. 1,8-cineole was the weakest while alpha pinene was the strongest, with beta pinene following closely behind in strength.
The beta-pinene found in juniper berry oil has moderate antibacterial properties and hence it may have moderate anti-acne properties.
SABINENE – a plant compound also found in holm oak, carrot seed and Norway spruce oils. Sabinene provides some of the spicy tang of black pepper and nutmeg. This study analysed the anti-inflammatory powers of water hemlock oil and sabinene, which the oil contains in 29.0% concentration.
Apparently “both the oil and sabinene demonstrated strong anti-inflammatory activity” when tested against irritated skin. We couldn’t care less about water hemlock oil right now, but juniper berry oil is a rich source of sabinene.
This study analysed angelica essential oil (the amount of essential oils is endless) and concluded that sabinene was the predominant compound. M-cresol, α-pinene, α-bisabolol and α-bornyl acetate were the others, and sabinene had the lowest inhibitory activity against microorganisms. However, the whole angelica oil, sabinene and m-cresol all had strong antioxidant activity, and isolated sabinene beat both the whole oil and the isolated m-cresol.
Sabinene is a fairly obscure compound and has little research to its name. It has some powers connected to acne, but compared to alpha-pinene it remains shrouded in mystery.
LIMONENE – definitely well-researched, because it’s found widely in common plants like lemons and lime. Limonene is safe for consumption, but is known to be a skin irritant and sensitizer when applied topically (study). If you experience a random breakout after using juniper berry oil, the limonene could be why.
However, the concentrations in juniper berry oil are low, at just 5.52%. Limonene isn’t a complete car crash, because this study and this study found that topical limonene could reduce free radical activity on the skin.
P-CYMENE – a compound also found in cumin oil and another acne-clearing favourite, thyme oil. This study found that eating p-cymene from F led to increased antioxidants in the brains of mice. Antioxidants like superoxide dismutase and catalase went up, whereas free radicals like thiobarbituric reactive substances (TBARs) went down.
Does p-cymene work when applied topically? This study analysed the components of Greek essential oils and concluded that p-cymene and y-terpinene had no significant antioxidant effect when applied topically. Thymol and carvacrol were the active components.
Both catalase and SOD are made by the body itself, so it’s possible that p-cymene only allows your body to make your own antioxidants – it might lack any strong antioxidants powers itself. P-cymene has also been reported to be skin irritant like limolene.
The exact concentrations of p-cymene in juniper berry oil are unclear – it varies significantly between different species – but it’s one of the most commonly detected compounds. The acne powers of p-cymene are also shrouded in mystery.
If it wasn’t for the original study which proclaimed it to be a promising new anti-acne treatment, juniper berry oil would deserve next to no attention.
Its effects on the root causes of acne are very mixed, particularly in its antibacterial properties. Moreover, there are over 70 different species across Europe, Asia, and North Africa. Even within the USA there are many species. It’s a big hassle to identify the perfect one for acne. J. oxycedrus and J. phoenicea perform well, but the search is pointless when you have a proven to be effective bottle of tea tree oil sitting right on your shelf.
Tea tree oil has been proven to reduce acne by between 23.7% and 62.1%. It has 3 solid studies demonstrating that it can soothe inflammation when applied topically.
Rose water, the essential oil distilled from rose water, has an impressive arsenal of studies showing that it can inhibit neutrophils, common immune system agents behind acne. Rosemary extract is one of the best of all essential oils, since the rosmarinic acid, carnosic acid and carnosol can all wipe out p.acnes bacteria…
…and that’s only the essential oils. Elsewhere, you have raw honey and its handful of proven antibacterial compounds like methylglyoxal. You have the legendary aloe vera, with its four thousand year track record of soothing wounds and pimples. Grapeseed oil and sea buckthorn oil are both excellent sources of vitamin E and vitamin A respectively.
There’s little point in using juniper berry oil for acne when you have so many options elsewhere. Judging from all the data, there’s no single standout compound or power. Alpha terpene is the strongest compound, but tea tree oil contains just as high amounts.
There’s a one in a million chance that all other natural topical treatments give you an allergic reaction and fail to reduce your pimples. In that case, go for it, because juniper oil seems to be risk free.
Overall, juniper berry oil may reduce your acne and its antioxidants are strong, but there are countless better uses of your time and money.
Thanks for reading!