Castor oil is uniquely thick and viscous oil extracted from the seeds of the castor bean plant (Ricinus communis). It’s been used for thousands of years for its medicinal, cosmetic, and industrial properties.
When I first heard of castor oil, I mistakenly thought it came from beavers, since the translation of castor in French to English is 'beaver.' Furthermore, I was confusing it with castoreum, a yellowish exudate from the castor sacs of mature beavers. Castoreum is used as a perfume fixative and flavoring ingredient in the food industry.
TLDR - Castor oil is a vegetable oil pressed from castor beans.
This article with discuss:
- What is castor oil?
- How is castor oil made?
- What does castor oil smell like?
- What color is castor oil?
- What does castor oil feel like?
- What is the composition of castor oil?
- Does castor oil clog pores?
- Should castor oil be used at 100% or best diluted?
- Castor oil and oil cleansing
- Summary
- References
What is castor oil?
INCI: Ricinus communis (Castor) Seed Oil
Extraction Method: Various - Cold pressed, expeller pressed, refined
Appearance: Pale yellow to light amber
Texture: Thick, viscous, slightly sticky
Aroma: Mild to neutral, slightly nutty
Castor oil is derived by cold-pressing the seeds of the castor bean plant (Ricinus communis). While castor seeds contain ricin, a potent toxin, the oil itself is completely safe for use in skincare products. During the extraction process, ricin is left behind in the waste pulp, while the castor oil is purified and free of any harmful substances.
Rich in ricinoleic acid, castor oil offers nourishing and calming benefits. Its high viscosity and occlusive properties make it ideal for cleansing, soothing and helping skin retain moisture.
How is castor oil made?
Castor oil is made by extracting oil from the seeds of the castor bean plant (Ricinus communis). The process typically involves cold pressing or hot pressing the seeds to release the oil.
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Cold Pressing: The seeds are cleaned and mechanically pressed at low temperatures to extract the oil. This method preserves most of the oil's natural nutrients, including ricinoleic acid and other beneficial compounds.
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Hot Pressing: In this method, the seeds are heated before being pressed to extract the oil. While this process can yield more oil, it may result in the loss of some nutrients due to the heat.
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Refining: After extraction, the oil is typically refined to remove impurities and any remaining ricin (a toxic protein). The refining process ensures that the oil is safe for use in skincare and other applications.
The result is a thick, pale yellow oil that is rich in ricinoleic acid, giving it its characteristic hydrating, soothing, and anti-inflammatory properties.
What does castor oil smell like?
Castor oil has a mild to nutty, and slightly earthy scent.
The aroma can be more noticeable in its unrefined form, which retains more of the natural plant characteristics.
Refined castor oil, on the other hand, tends to have a much more neutral or barely noticeable scent due to the purification process. While not unpleasant, the smell is often subtle and neutral, allowing it to blend well with other ingredients in skincare formulations.
What color is castor oil?
Castor oil is typically a pale yellow or golden color, though its shade can vary slightly depending on the processing method.
When cold-pressed, it tends to be a lighter yellow, while refined castor oil may appear clearer or even slightly colorless.
What does castor oil feel like?
Castor oil has a thick, viscous texture that feels heavy and rich when applied to the skin.
Castor oil is primarily considered an occlusive ingredient, meaning it forms a barrier on the skin to help lock in moisture. Due to its thick, viscous nature, it doesn't absorb quickly like lighter oils; instead, it sits on the surface for a while, providing protection.
Over time, it may gradually absorb, but it can leave a slightly greasy or sticky feel for longer compared to more lightweight oils.
Castor oil is often used in small amounts and combined with lighter oils to balance the texture.
What is the composition of castor oil?
Castor oil has a unique chemical composition and contains high amounts of the fatty acid ricinoleic acid, as well as minor amounts of phospholipids, phytosterols, vitamin E and phytochemicals.
Fatty Acids
- 75 - 95% ricinoleic acid (C18:1-OH)
- 3 - 9% linoleic acid (C18:2)
- 2 - 7% oleic acid (C18:1)
- 0.5 - 3% stearic acid (C18:0)
- 0.3 - 2.5% palmitic (C16:1)
- < 1% alpha-linolenic (C18:3)
(Reviewed by Yeboah et al, 2020)
Ricinoleic acid, along with certain of its salts and esters function primarily as skin-conditioning agents, emulsion stabilizers, and surfactants in cosmetics (Final Report on the Safety Assessment of Castor Seed Oil, 2007).
Phospholipids
Phospholipids are natural fats that play a vital role in maintaining the structure and function of cell membranes.
There are many different types of phospholipids!
Phosphatidylcholine is a natural phospholipid found in cell membranes and is known for its emulsifying, moisturizing and protective properties.
Castor oil contains less than1% phospholipids, with phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine as the major components (Yeboah et al, 2020).
Phytosterols
Phytosterols are plant-derived sterols with benefits for you skin. They have a similar structure and function as cholesterol. There are more than 100 types of phytosterols!
Phytosterols such as sitosterol are potent antioxidants (Bakrim et al, 2022).
Castor seed oil has been shown to contain phytosterols at 2.21 mg/g, with a predominance of β-sitosterol at 1.04 mg/g, as well as minor amounts of campesterol, stigmasterol and Δ-5 avenasterol (Said et al, 2016).
Vitamin E
Vitamin E is an essential nutrient and it has benefits for your skin.
When applied topically, vitamin E is a skin conditioning agent, a powerful antioxidant and it can protect your skin against photodamage from the sun.
There are 8 types of natural vitamin E. There are four tocopherols (alpha, beta, gamma and delta) and four tocotrienols (alpha, beta, gamma and delta).
Castor oil is a source of tocopherols, with total tocopherols at 0.183 mg/g.
- 0.0013 mg/g beta-tocopherol
- 0.0028 mg/g mg/g alpha-tocopherol
- 0.0431 mg/g delta-tocopherol
- 0.0527 mg/g gamma-tocopherol
(Said et al, 2016)
Phytochemicals
Phytochemicals are naturally occurring compounds found in plants that contribute to their color, flavor, and protection. These compounds are not essential for human nutrition but can offer significant health benefits, including antioxidant activity.
Castor oil has been shown to contain various phytochemicals, including flavonoids, cyanogenic glycosides, saponins, oxalates, phytates, alkaloids, and tannins (Momoh et al, 2012).
These nutrients enhance castor oil's beneficial actions, making it a valuable ingredient in skincare for soothing and protecting the skin.
Does castor oil clog pores?
Castor oil is generally considered non-comedogenic, meaning it is unlikely to clog pores for most people.
Its unique composition, particularly the high concentration of ricinoleic acid, makes it an effective emollient and cleanser without typically causing breakouts. However, due to its thick, viscous nature, it may be too heavy for some individuals, especially those with oily or acne-prone skin.
It’s always a good idea to test a small amount on a patch of skin to see how it reacts before incorporating it into your routine. For most, castor oil can be a beneficial ingredient in skincare, offering hydration and soothing benefits without the risk of clogged pores.
For most skin types, castor oil should be used diluted.
Should castor oil be used at 100% or best diluted?
While castor oil is potent and effective, it is typically best diluted when used on the skin.
Due to its thick, viscous texture, applying it undiluted can feel heavy and might not be ideal for all skin types, especially those prone to acne or excessive oil production.
Too much castor oil can also feel drying for dry skin types.
For oil cleansers, moisturizers, or hair treatments, castor oil is often mixed with lighter carrier oils like jojoba, almond, or argan oil to balance its thickness and ensure better absorption. Diluting castor oil helps maintain its beneficial properties while improving its spreadability and making it more comfortable to use.
For facial use (e.g., as part of an oil cleanser or moisturizer): A 10-20% dilution of castor oil in a lighter carrier oil (like jojoba, almond, or argan oil) is typically recommended. This allows you to benefit from castor oil's soothing properties without overwhelming the skin.
Castor oil and oil cleansing
Castor oil is a great ingredient for oil cleansers due to its thick, viscous texture and effective cleansing properties.
As an occlusive agent, it helps break down and dissolve makeup, dirt, and impurities while also providing a rich, smooth texture that makes the cleansing process feel luxurious.
The oil’s ability to create a protective barrier on the skin ensures that it doesn’t strip away moisture, leaving your skin feeling hydrated and nourished after cleansing.
Additionally, castor oil’s slight stickiness and heavier consistency help bind to impurities, offering a deep, thorough cleanse without feeling too harsh.
It’s the perfect base for oil cleansers, providing both an effective clean and a comforting experience for dry or sensitive skin.
At Dry Skin Love Skincare, we use extra virgin organic castor oil in our oil cleansers.
Summary
Castor oil is a unique, thick, and versatile oil derived from the seeds of the castor bean plant.
Its rich, viscous texture make it a standout ingredient in skincare and beauty formulations.
The oil is rich in ricinoleic acid, which contributes to its thickness and beneficial properties.
While castor oil can feel greasy or sticky, it plays an important role in various products, especially oil cleansers, where it aids in breaking down impurities while leaving the skin moisturized. Despite its richness, castor oil is generally non-comedogenic, meaning it’s unlikely to clog pores for most skin types.
Castor oil has benefits for skin and continues to be a key ingredient in both traditional and modern beauty routines.
References
Atmanto D. Effectiveness of utilizing VCO oil and castor oil on natural creams for dry skin treatment due to environmental factors. In Journal of Physics: Conference Series 2019 Dec 1 (Vol. 1402, No. 2, p. 022093). IOP Publishing.
Azadmard-Damirchi SO, Achachloubi BF, Alirezalu K, Alirezalu A, Hesari J, Emami S. Physiological and medicinal properties of castor oil. book: Recent Progress in Medicinal Plants. 2011:323-7.
Bakrim S, Benkhaira N, Bourais I, Benali T, Lee LH, El Omari N, Sheikh RA, Goh KW, Ming LC, Bouyahya A. Health Benefits and Pharmacological Properties of Stigmasterol. Antioxidants (Basel). 2022 Sep 27;11(10):1912.
Caupin HJ. Products from castor oil: past, present, and future. InLipid technologies and applications 2018 May 2 (pp. 787-795). Routledge.
Mein EA, Richards DG, McMillin DL, Nelson CD. Transdermal absorption of castor oil. Evidence-Based Integrative Medicine. 2005 Dec;2:239-44.
Momoh, A. O., Oladunmoye, M., & Adebolu, T. (2012). Evaluation of the antimicrobial and phytochemical properties of oil from castor seeds (Ricinus communis Linn). Bulletin of Environment. Pharmacology and Life Sciences, 1(10), 21-27.
Parvizi MM, Saki N, Samimi S, Radanfer R, Shahrizi MM, Zarshenas MM. Efficacy of castor oil cream in treating infraorbital hyperpigmentation: An exploratory single-arm clinical trial. J Cosmet Dermatol. 2024 Mar;23(3):911-917.
Said G, Daniel P, Badr K, Mohamed I, Zoubida C. Chemical characterization and oxidative stability of castor oil grown in Morocco. Moroccan Journal of Chemistry. 2016 Apr 11;4(2):J-Chem.
Scarpa A, Guerci A. Various uses of the castor oil plant (Ricinus communis L.) a review. Journal of ethnopharmacology. 1982 Mar 1;5(2):117-37.
Vieira C, Evangelista S, Cirillo R, Lippi A, Maggi CA, Manzini S. Effect of ricinoleic acid in acute and subchronic experimental models of inflammation. Mediators Inflamm. 2000;9(5):223-8.
Vieira C, Evangelista S, Cirillo R, Terracciano R, Lippi A, Maggi CA, Manzini S. Antinociceptive activity of ricinoleic acid, a capsaicin-like compound devoid of pungent properties. Eur J Pharmacol. 2000 Oct 27;407(1-2):109-16.
Vieira C, Fetzer S, Sauer SK, Evangelista S, Averbeck B, Kress M, Reeh PW, Cirillo R, Lippi A, Maggi CA, Manzini S. Pro- and anti-inflammatory actions of ricinoleic acid: similarities and differences with capsaicin. Naunyn Schmiedebergs Arch Pharmacol. 2001 Aug;364(2):87-95.
Yeboah A, Ying S, Lu J, Xie Y, Amoanimaa-Dede H, Boateng KG, Chen M, Yin X. Castor oil (Ricinus communis): a review on the chemical composition and physicochemical properties. Food Science and Technology. 2020 Oct 30;41:399-413.
Author Information
Dr. Natasha Ryz is the founder of Dry Skin Love Skincare. With over 10 years of experience as a formulator and a strong scientific foundation, Dr. Ryz creates products that combine the best of nature and science for transformative results.
She trained in Organic Skincare Formulation at Formula Botanica and took the Skincare Specialist Program at the School of Natural Skincare, with over 200 hours of specialized education. Dr. Ryz also holds a diploma in Beauty Brand Business Management.
Dr. Ryz’s scientific background includes a PhD in Experimental Medicine from the University of British Columbia, and she has over 15 years of research experience in microbiology, immunology, and biochemistry. This expertise informs every product she formulates, ensuring exceptional quality, efficacy, and luxury.