Castor oil is often described as a miracle cure—at least on social media. Originally known as a laxative, the oil is said to reduce wrinkles and age spots when applied externally and also stimulate hair growth. Here, we discuss the effects of castor oil and why it’s worth having in your home.
What is castor oil?
Castor oil is obtained from the seeds of the castor plant (Ricinus communis), which is native to the tropics and subtropics.
The tree can grow up to 8 meters tall and is also called the miracle tree because it grows miraculously quickly, although not as quickly as the Old Testament says.
According to the statements there, the plant grew into a shade-giving tree overnight at God’s instruction.
At first glance, the seeds of the castor oil plant resemble a full-fledged tick.
They consist of 30 to 50 percent oil – castor oil. Compared to some other oils, castor oil is a rather thick oil.
It can range from colorless to slightly yellowish, and in cold-pressed quality, it has a rather unpleasant, somewhat bitter taste. Refined oils, on the other hand, are tasteless.
What’s special about castor oil is that it consists of up to 90 percent ricinoleic acid, a monounsaturated fatty acid that, like oleic acid (found in olive oil), is one of the omega-9 fatty acids. The unusual properties of castor oil are primarily due to this fatty acid— both the laxative properties when taken internally and the skin-care and other properties mentioned below when applied externally.
Since when has castor oil been known?
The ancient Egyptians, Greeks, Romans, and Chinese already appreciated the oil of the castor oil plant and used it for a variety of purposes, such as as a laxative, for abortions, to support wound healing, and even as a skin care product.
Even Cleopatra is said to have used the oil as the basis for her makeup because of its smoothing effect and is therefore still often mixed into cosmetics today – from lipsticks to makeup.
What effects does the oil have when used externally?
Castor oil is most commonly applied externally in the form of castor oil packs. It is said that the oil can penetrate the skin, enter the bloodstream, and therefore heal the entire body.
Below, we briefly introduce some of the oil’s properties. Further down, you’ll find details on its most important applications, including its correct use.
Relieve inflammation
Castor oil can reduce inflammation. It contains a high level of ricinoleic acid, a monounsaturated fatty acid with powerful anti-inflammatory properties.
Improve blood circulation
Ricinoleic acid can penetrate deep into the skin, stimulating local blood vessels and promoting blood flow.
Promote detoxification and regenerate the liver
Applying castor oil packs to the abdominal area can stimulate lymphatic flow, which supports the removal of toxins and relieves strain on the liver. This can contribute to liver regeneration and promote the body’s detoxification process.
Regulate digestion
While castor oil is known as a powerful laxative when used internally, external compresses applied to the abdominal area can gently support digestion without directly irritating the intestines. This application can be helpful for constipation or sluggish digestion.
Increase antioxidant status
Regular use of castor oil packs can boost the body’s production of antioxidants by stimulating metabolism and reducing oxidative stress. An improved antioxidant status supports the protection of cells from free radicals.
Calm nerves and help with polyneuropathy
In cases of nerve pain or polyneuropathy, castor oil packs can provide relief thanks to their anti-inflammatory and circulation-promoting properties. They calm the nerves and can thus reduce pain and discomfort.
Improve sleep
The relaxing effect of warm castor oil packs can help calm the body before bedtime, promoting deeper and more restful sleep.
Make hair grow thicker and fuller
Applying castor oil to the scalp can help promote hair growth, making hair thicker and healthier. For more information, see “Castor Oil for Hair Growth” below.
Prevent split ends
The oil’s moisturizing properties make hair soft and can prevent split ends. Regular application to the ends of your hair protects against dryness and brittleness.
Moisturize skin, shrink pores, reduce blemishes, age spots and wrinkles
Castor oil penetrates deep into the skin and provides intense moisture. This can help shrink pores, reduce blemishes, and improve the appearance of age spots and wrinkles. For more information on its effects and application on the skin, see “Castor Oil for Skin Care” below.
Shrink warts, calluses, corns, and skin ulcers
The softening and healing properties of castor oil, when used regularly, can help soften and reduce the size of hardened skin areas such as calluses, hard skin, and corns. It can also be helpful for skin ulcers.
Relieve foot pain
By promoting blood circulation and relaxing muscles, castor oil packs can effectively relieve foot pain. Regular use can lead to a noticeable improvement in well-being.
Despite the length of this list, it’s safe to assume that not all of the oil’s positive effects and possible uses are known, and there are no scientific studies for most of them. Castor oil is therefore a true home remedy!
What are castor oil packs?
For thousands of years, castor oil packs have been used worldwide in traditional Chinese medicine, Ayurveda, and the holistic medicine of ancient Egypt and the Mediterranean.
Castor oil packs are among the oldest medicinal remedies in the world and are also the most common way to apply castor oil. They can be used on almost anyone – including children and older people (except pregnant women).
There’s almost no illness that oil packs aren’t supposed to help with. The lists of illnesses found online are extremely long and include, in addition to the complaints mentioned above, hormonal disorders, gastrointestinal disorders, thyroid problems, sleep disorders, and joint pain, as well as mental illnesses such as anxiety, depression, and ADHD. However, there are virtually no scientific studies on these either.
*Castor oil can be found here at this link.
How to use castor oil packs?
Castor oil packs have become very popular, and some instructions sound incredibly complicated. Basically, it would make sense to massage the oil in one to three times a day, depending on the specific area of the body and the symptoms, or to dab the oil on the area.
The simplest version of an oil pack is to place a cloth soaked in the oil on the affected area of the body, secure it with a dry cloth, and let it rest for 1 hour to allow the oil to work. We describe the detailed version below.
You will need the following utensils:
- Castor oil, e.g. *this oil
- Small bowl
- Small cotton or flannel cloth (e.g. 20 x 15 cm) or *these cloths
- Plastic wrap
- Gauze bandage and bandage clips for fastening
- Towel that can be wrapped around the stomach/chest area or special cloth for stomach/chest wraps
- Hot water bottle
- If necessary, a protective pad for the bed/sofa (towel or incontinence pad) if you don’t want to bother with gauze bandages and clips, so that there are no stains on the bed or sofa from any oil leakage.
*You can get castor oil packs here.
The instructions
Now, for a castor oil pack, proceed as follows:
- Place the cloth in the bowl and add 1 to 2 tablespoons of castor oil to it.
- Wait until the cloth has absorbed the oil; it should be well soaked, but not dripping; wring it out if necessary.
- Place the cloth directly on your skin. For a liver pack, for example, on the right upper abdomen, or for an intestinal pack, on the navel area.
- Place a piece of plastic wrap over the cloth to prevent the oil from seeping out, as it will leave stains.
- Now, for more warmth and firmness, place a towel around it or a cloth that is commercially available for abdominal or chest wraps.
- Lie comfortably on your bed or sofa and try not to move too much. Listen to music or meditate during this time. The main thing is that you are relaxed.
- For intestinal wraps, you can also place a small hot water bottle on your stomach. For liver wraps, lean the hot water bottle upright against the side of your upper right abdomen, practically tucked under your armpit. You might want to wrap a towel around the hot water bottle if it gets too hot.
- Leave the pack on for at least 1 hour. Sometimes 2 to 3 hours is recommended.
- The oil can stay on your body, so it doesn’t need to be washed off afterward. If too much oil sticks to your body, you can wipe it off with a paper or cloth.
- The cloth can be used for several packs, so it does not need to be washed or even disposed of after the first use.
- A little oil can also be massaged directly into the skin with your hands before applying the pack.
As a precaution, castor oil packs should not be used during pregnancy – see “Castor oil during pregnancy” below.
How often do you use the packs or oil?
There’s no general rule regarding the frequency of castor oil pack use. You can, for example, apply them three days in a row (once every day) or as needed.
You can also use the pack three times a week, for example, for 10 consecutive weeks. It’s best to focus on your individual symptoms, discuss the matter with a practitioner, and observe how well the pack works for you.
It’s important to always have rest periods between pack days so that your body has time to react. Therefore, you shouldn’t start using an oil pack every day.
However, if you want to treat a wart, a papilloma, a corn, or something similar, you should initially apply it daily or reapply it daily. For warts, for example, you could soak a plaster in castor oil, reapply it once or twice a day, and do this daily for two months.
In the case of acute problems, such as an inflamed finger due to a foreign body (splinter) or an inflammation of the nail bed, you can wrap a cloth soaked in the oil around the finger, secure it with a gauze bandage and leave it on overnight.
If you use the oil for facial care, you can also take breaks from time to time or use it just occasionally as a little extra for your skin.
How quickly does the oil work?
Overall, changes should be observed after 3 to 8 weeks for chronic problems.
Castor oil as a laxative
The oil has been used for centuries as a laxative to treat constipation. It is one of the relatively fast-acting natural laxatives. How quickly it works depends on the time of administration. If taken on an empty stomach (approx. 15 ml or 1-2 tablespoons), the effect can be felt after just 2 to 6 hours.
Some recipes for removing intestinal parasites also contain castor oil, as we explain at the end of this page.
You should avoid taking it in the evening, as you’ll need to go to the bathroom more often during the night. The oil is also not suitable for long-term use. As with other laxatives, it can lead to a habituation effect and the typical side effects of laxatives (see “Risks and Side Effects” below).
The laxative effect is due to the ricinoleic acid it contains. It activates the smooth muscle cells in the intestinal wall (via activation of the so-called G-protein coupled receptors), resulting in increased contractions (peristalsis). Furthermore, ricinoleic acid binds more water in the intestine and increases stool volume.
Since these receptors are also present in the uterus, ricinoleic acid has an activating effect there as well (1), which could lead to premature labor during pregnancy. Therefore, taking the oil during pregnancy is not recommended. (More on this under “Risks and Side Effects” below).
Interestingly, you don’t even necessarily have to ingest the oil to relieve constipation. The castor oil packs described above, applied externally, often help. A study conducted in two nursing homes has shown that this treatment can also be very helpful for older people.
Although the packs did not increase the number of bowel movements in participants, most of whom had suffered from constipation for 10 years or more, stool consistency improved (became softer), stools were easier to pass, and there was a feeling of complete emptying after bowel movements.
The symptoms of constipation were thus alleviated in a pleasant way (2), whereas when the oil is taken orally one must always expect abdominal cramps, nausea and diarrhea.
In the study, the packs were applied on three consecutive days and left on the stomach for one hour each time, together with a hot water bottle.
We present more natural laxatives in our article on natural laxatives at the end of this page.
Castor oil for laxatives before colonoscopy?
Castor oil can also be used as a bowel cleansing agent before a colonoscopy, at least as an adjunct, as a 2022 study showed (3).
It was observed that the oil reduced the amount of laxatives otherwise required and increased intestinal cleanliness (4) – however, the study referred to colon capsule endoscopy – a new variant of intestinal examination in which a capsule containing two tiny cameras is swallowed, which then take pictures of the colon.
This avoids the need for sedation, the insertion of a colonoscope, and the potential side effects of colonoscopy. However, colon capsule endoscopy also has disadvantages. It is not as precise, and of course, polyps cannot be removed or tissue samples taken during the procedure.
Castor oil for skin care
Castor oil is said to have positive effects on the skin, such as reducing wrinkles, moisturizing the skin, and stimulating collagen production. It is also said to make the skin smoother and softer, reduce puffiness, and shrink enlarged pores, thus diminishing blackheads. It is also said to dissolve excess sebum, making it easier to cleanse the skin.
A 2023 Iranian study showed that rubbing a specific cream into patients with pronounced dark circles under the eyes (due to hyperpigmentation) could help reduce pigmentation. The 22 patients applied a cream containing 10 percent castor oil for two months (5).
The test subjects experienced an improvement after the treatment period. Melanin levels, wrinkle formation, and skin elasticity were also reduced or improved (6). Melanin is the dark pigment of the skin, which is also found in increased concentrations in age spots, moles, etc.
How to apply the oil on your face
If you want to use the oil as a facial oil, then use only a very small amount and combine the application with a facial massage so that the oil can be absorbed.
However, the oil does not absorb completely immediately, but takes a few hours.
Applying makeup afterward isn’t ideal, so it’s best to apply the oil in the evening after cleansing your face. To prevent the pillow from becoming oily, place a cloth over it for protection.
The next morning, your skin feels noticeably smoother and more refreshed, something often unmatched even by the most expensive facial care products. Castor oil is also considered non-comedogenic, meaning it doesn’t clog pores or cause pimples or blackheads.
On the comedogenicity scale, which ranges from 0 to 5, castor oil receives a 1 for very low comedogenicity. Linseed oil, wheat germ oil, and palm oil, for example, have a 4-5 on this scale. Coconut oil is at 3-4, and olive oil at 2-3.
If you want to use castor oil twice a day, let it absorb for 20 minutes in the morning, wash your face, and then apply your usual daily moisturizer, including makeup. You’ll automatically massage the rest of the oil into your hands and enjoy soft, smooth skin.
Castor oil is even said to have a positive effect on acne, and scars can also be rubbed with it regularly, which apparently makes them paler.
*Castor oil can be found here at this link.
Castor oil for healthy fingernails
The oil is also recommended for fingernails. Rubbing it into your nails daily—for example, in the evening before bed—leads to stronger fingernails and healthier cuticles.
Castor oil for hair growth
The oil is often referred to as a hair growth product on social media, and many people report success.
However, this is not the case with androgenetic hair loss; rather, it is observed that the hair becomes stronger overall.
To our knowledge, there are no concrete studies on humans that would show a hair growth-promoting effect.
A 2008 Romanian study showed that a lotion containing 35 percent castor oil made the fur of rabbits (in 50 percent of the treated animals) softer, longer, and thicker after four weeks (7). Treatment with a 40 percent oil, however, produced no noticeable results.
Scientists in the Ivory Coast also conducted research on rabbits in 2021. In this study, too, an improvement in hair growth was observed in the animals treated with castor oil (8), more so in the males than in the females. (However, with only 8 test animals in total, divided into four groups, the study’s significance is rather low.)
In an article on the website Good Housekeeping, a trichologist (a hair-related consultant) and a dermatologist are interviewed about the effects of hair care products containing castor oil. The two specialists believe that the oil does not exactly lead to thicker and longer hair (9), but it does:
- smooth the hair and make it shiny
- nourish the hair, make it softer and make it feel less dry
- promotes scalp health because, among other things, its antibacterial properties can reduce harmful bacteria or fungi on the scalp
- Prevent split ends and hair breakage by surrounding the hair shaft with a protective layer
- helps cleanse hair and scalp as it absorbs dirt, which can then be removed more easily
You can simply pour a little oil into a small bowl, dip your fingertips in it, and massage it into your scalp. Then leave it on for two hours and wash your hair as usual. It can be easily removed with regular shampoo.
If you want to treat the ends of your hair, spread the oil on the ends, tie it in a bun (if your hair length allows it), put on a cap and leave the oil on overnight (at least 2 hours).
*Castor oil can be found here at this link.
Castor oil for eyelashes and eyebrows
According to user reports, the oil is said to have a significant hair growth-promoting effect on eyelashes and eyebrows, even if eyelashes and eyebrows were previously very sparse.
The best way to do this is to use an empty mascara container (empty mascara bottle with eyelash brush), fill it with the oil and then apply it very carefully to your eyelashes and eyebrows in the evening.
Conventional castor oil should not be used in the eyes. If you want to use the oil for the eyes, for example, for dry eyes, you would need to use a castor oil specifically labeled for this purpose – see the next section.
Castor oil for the eyes
Castor oil is said to be particularly helpful for dry eyes and blepharitis. Blepharitis is an inflammation of the eyelid margins, which can lead to redness, swelling, and crusting. Dry eyes often also occur.
In a 2021 New Zealand study, 26 patients experienced significant improvement after four weeks of applying 100% cold-pressed castor oil twice daily (morning and evening). Crusts and redness were reduced (10), and eyelid swelling was less severe.
Dry eye symptoms also improved. No adverse side effects were observed. However, this study lacked a control group.
If you have the eye problems mentioned above, be sure to discuss the use of the oil with your ophthalmologist, as an oil suitable for the eyes must be used.
Castor oil for cleaning dentures
Numerous bacteria and fungi (e.g., Candida albicans) can multiply on dentures. If dentures are not cleaned properly, this can lead to health problems, such as denture stomatitis, an inflammation of the oral mucosa involving Candida.
If someone is also weakened (which is often the case with older people, who often also wear prostheses) or has to take immunosuppressant medication, the fungi can become dangerous and migrate to the gastrointestinal tract or lungs. It is therefore important that the prosthesis is always cleaned thoroughly.
A 2017 study showed that castor oil can be used effectively for this purpose. While a 0.25 percent and a 0.5 percent sodium hypochlorite solution (liquid chlorine) were more effective at removing the biofilm of bacteria and fungi than castor oil, the oil was more effective than a pure saline solution. Castor oil was even more effective against Candida than sodium hypochlorite (11).
*Castor oil can be found here at this link.
Castor oil for wound healing
The oil can be used on wounds because it keeps them moist and prevents them from drying out, which promotes the healing process. At the same time, the ricinoleic acid it contains reduces inflammation and relieves pain (12).
In the US, there is a Vaseline-based wound ointment (Venelex) that combines castor oil with Peruvian balsam. This is a special oil that meets the standards of the American Pharmacopoeia. It is labeled USP for United States Pharmacopeia.
Peruvian balsam (Balsamum peruvianum) is the bark sap of the balsam tree (Myroxylon balsamum), a traditional wound healing remedy. We haven’t found a local source for this ointment. Whether it’s advisable to apply castor oil directly to wounds is something you’ll need to discuss with your practitioner– it certainly depends on the type of wound.
Risks and side effects
Typical risks and side effects of the oil – when taken orally and in larger quantities – include abdominal cramps, nausea and diarrhea.
As with all laxatives, excessive use of castor oil as a laxative can lead to addiction. This can lead to constipation, electrolyte imbalance, dehydration, and even life-threatening impairment of kidney and cardiovascular function (13).
Under no circumstances should the oil (or any other laxative) be used for weight loss (14).
A 2017 Indian study states that even a single use of the oil for hair care can potentially lead to matting. However, this occurs very, very rarely. According to the study, there are only 17 known cases worldwide (15).
When applied externally to the skin, some people may experience allergies (16), but this is not very common. A 2017 Belgian study reported two cases.
Who should not take castor oil?
While external use is generally well-tolerated, you should only take castor oil internally after consulting your practitioner. This is especially true for children and if you have a chronic condition such as inflammatory bowel disease (Crohn’s disease, ulcerative colitis), appendicitis, bile duct disease, or abdominal pain of unknown origin.
Children under 10 years of age should not take the oil internally at all.
Castor oil during pregnancy
It is not recommended during pregnancy, as the oil is said to induce premature labor. However, if labor is delayed, the oil may still be helpful, but it should ALWAYS only be taken if prescribed by a practitioner.
A 2022 meta-analysis from Iran describes the oral administration of castor oil as a safe method to dilate the cervix and induce labor (17). This method can prevent a cesarean section.
In an Israeli randomized study with a total of 81 women who were past their due date, labor could be effectively induced with the oil compared to the placebo (sunflower oil) (18).
In Italy, a five-year retrospective study examined the effects of administering a single 60 ml dose (in 200 ml of warm water) to women who were “overdue” at 40 and 41 weeks. It was found that the use of castor oil was more likely to induce labor within 24 hours (19) (compared with waiting).
Where can you buy the oil?
Castor oil can be purchased at pharmacies, drugstores, and online. When purchasing, it’s usually recommended to make sure the oil is cold-pressed, organic, packaged in dark glass bottles, and hexane-free. Hexane is a solvent used in refined oils, but not in cold-pressed ones. More on this in the next section.
*Castor oil can be found here at this link.
Can refined castor oil also be used?
Refined castor oil contains hardly any accompanying substances (vitamin E, secondary plant compounds) and is primarily sold in pharmacies for internal use. The crucial fatty acid (ricinoleic acid) is also present in the refined oil, which is why this oil is also effective.
Since solvents (hexane) are used during refining, there are often concerns that the finished oil may still contain residues of the toxic solvent. This may well be the case, although usually only traces, but if you have the choice, we would opt for a cold-pressed and therefore solvent-free grade (19).
*Hexane free Castor oil can be found here at this link.
What is the best way to store the oil?
As with all oils, storage should be in a dry, dark, and cool place. For unopened oils, follow the manufacturer’s instructions. The shelf life can be up to two years. Once opened, castor oil should be used within six months – assuming proper storage, although refined oils often have a longer shelf life than cold-pressed ones.
Which fatty acids are contained in the oil?
The fatty acid composition of castor oil is as follows (20) (but can naturally vary depending on origin and quality):
- 85 to 90 percent ricinoleic acid (an omega-9 fatty acid)
- 4 to 5 percent linoleic acid (an omega-6 fatty acid)
- 3 to 4 percent oleic acid (an omega-9 fatty acid)
- 1 to 2 percent stearic acid
- 1 to 2 percent palmitic acid
- 0.5 to 0.7 percent linolenic acid
Where does castor oil come from?
The castor oil plant originates from northern Africa and the Middle East, but today also grows in other warm tropical and subtropical regions, such as South America and the Mediterranean. There, it grows into a sparse tree that can reach up to 8 meters in height.
In our region, the plant is occasionally planted as an ornamental plant in parks and grows into a 2- to 3-meter-tall shrub in its first year. Due to its sensitivity to frost, the castor oil plant dies in winter.
The plant has beautiful, large, serrated leaves and is a pioneer plant. It germinates very quickly and tends to spread. In its native countries, it often grows along roadsides or on ruderal areas (bare, uncultivated soil).
Is castor oil toxic?
Castor oil is non-toxic, meaning it no longer contains ricin (see next section). Ricin is water-soluble and therefore does not enter the oil (21). However, the press residues left over from oil production are rich in ricin and therefore initially toxic. The ricin is extracted before being sold as fertilizer.
What is ricin?
The castor bean plant contains the poison ricin in all parts, but especially in the seeds. Ricin is highly toxic and is even considered a potential biological warfare agent.
One potential problem is that if you accidentally eat the seeds, you don’t notice anything off-putting. They don’t taste bitter, but rather relatively pleasant. This could pose a danger if children play with the pretty seeds.
If the seeds are swallowed whole, the toxicity is less pronounced. Since ricin is primarily found in the seed coat, it is released particularly when chewed.
The lethal dose is estimated at 1 to 20 µg per kilogram of body weight (according to some sources 5 – 10 µg), which corresponds to approximately 5 to 10 seeds (22). In children – depending on their age – even half a seed can be fatal.
Depending on the dose ingested, symptoms may appear after a few hours or even after two days (colic, nausea, vomiting, diarrhea, dehydration, muscle pain, liver and kidney damage, cerebral (brain-originating) seizures, and finally circulatory failure).
Treatment is usually symptomatic, such as administering fluids to combat dehydration. If ricin ingestion occurred less than 1 hour ago, activated charcoal can be attempted. In animal studies, treatment with N-acetylcysteine (a synthetic antioxidant) has reportedly proven helpful (in cases of liver and kidney involvement).
How toxic is ricin by injection?
A report from 1978 about the Bulgarian writer Georgi Markov, who agitated in exile against the then dictatorial head of state Zhivkov and was poked in the lower leg from behind with the tip of an umbrella on Waterloo Bridge in London.
At first, it was thought to be an accident. However, a few days later, the writer died. His autopsy revealed that he had been poisoned. The prick with the umbrella was no accident. It had been used to inject a tiny porous metal ball into his calf, releasing less than one twenty-thousandth of a gram (40 µg) of ricin.
Conclusion: Castor oil is indispensable in the medicine cabinet
Castor oil has numerous beneficial effects, making it an important ingredient in the home medicine cabinet. External applications in the form of oil packs should be the primary focus. Internal use should always be discussed with a practitioner.
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