For generations, castor oil has been considered a miracle remedy for growing eyelashes and eyebrows. Grandmothers talk about it, it's found in a thousand online tutorials, and it's often described as a natural ally for strengthening and thickening hair. But how much of that is true? And, more importantly, can it really make eyelashes and eyebrows regrow?

At lashINbrow, we've decided to analyze this widespread belief with a more professional eye, comparing tradition and science, to understand what castor oil can truly do and where, instead, the legend ends.

The truth is that pure castor oil does not stimulate the growth of new hairs. It does not have the ability to activate follicles or create new hair bulbs. What it can do, but only with constant, daily, and prolonged use, is help existing eyelashes and eyebrows to be stronger, more flexible, and less prone to breakage.

However, not all castor oils are the same. It's important to distinguish between pure castor oil, which acts very superficially, and its more modern and functional hydrolyzed or hydrogenated versions, used in various professional cosmetic products.

Real benefits: pure vs. hydrolyzed/hydrogenated castor oil

The real question is not whether castor oil works or not, but in what form and to what extent. Pure castor oil, the traditional one found in herbal shops or amber glass bottles, has a very large and heavy molecule, which cannot penetrate the hair shaft. For this reason, its action remains superficial: it creates a protective film that can temporarily improve the appearance of eyelashes, but without nourishing them deeply.

Hydrolyzed or hydrogenated versions, however, overcome this structural limitation.

• Hydrolyzed castor oil is "broken down" into smaller, partially water-soluble molecules, making it lighter and easier to absorb.
• Hydrogenated castor oil is treated with hydrogen to make it more stable, less oily, and more protective.

A concrete example we can give you right away is Fashion Lash & Brow, the eyelash and eyebrow fixer from InLei®, which contains PEG-40 Hydrogenated Castor Oil, a molecule derived from hydrogenated castor oil. This modified form adheres better to the hair, nourishes it without weighing it down, and protects it from external factors, giving a shiny and well-groomed effect.

Modern cosmetics have made great strides, and today there are products far more effective than a simple oil, in which processed castor oil is just one of many functional ingredients in a complex formula, designed to deliver real results.

Many clients tell us they have tried pure oil for months without seeing major changes, and indeed, this is not uncommon: visible results require infinite consistency and a good dose of luck. But in professional products, where molecules are made more bioavailable, the difference is noticeable: shinier lashes, more compact brows, and greater resistance to daily stress.

It's no coincidence that in modern lamination or post-extension care treatments, such as those from the InLei® and Light Lashes® lines, it is precisely these types of refined ingredients that make the difference between a temporary or apparent result and a true beauty treatment.

Myth and reality about castor oil for eyelashes

It often happens that popular beliefs mingle with scientific reality, giving rise to myths that are difficult to dispel. And one of the most widespread is that castor oil stimulates the growth of new hair bulbs. In reality, this is not possible: no oil or cosmetic, however natural or powerful, can create new follicles. Only with surgery and transplants can these results be achieved!

Not even the most advanced lash serums, such as the InLei® Adiutrix lash and brow serum, can make new hairs grow: their action affects those already present, strengthening them and prolonging the natural growth phase (anagen phase).
This means that an existing hair can become longer, thicker, and stronger, but the number of bulbs cannot increase.

What professional serums do, and what castor oil cannot, is stimulate the metabolism of the hair follicle with specific active ingredients such as peptides and plant extracts. In this way:

• the life of each lash is prolonged, allowing it to grow longer and stronger;
• thin or weak hairs become thicker and more pigmented, visibly improving density;
• the regrowth cycle is optimized, reducing shedding.

With serums like Adiutrix, after only about 40 days of constant application, lashes become noticeably stronger, darker, and healthier. With pure castor oil, however, the results are slower, less visible, and often temporary.

If you want to delve deeper into this topic, we recommend reading the article How long do eyelashes regrow, where we explain the hair life cycle and how to best support it.

In summary: castor oil doesn't work miracles; modern cosmetics can certainly do more, with well-researched formulas, balanced ingredients, and concrete results.

Possible side effects of castor oil

When it comes to natural remedies, people tend to think they are always safe. But that's not always the case. Castor oil for eyelashes and eyebrows can cause side effects if used incorrectly, especially when applied pure, in large quantities, and too close to the eyes.

The first risk is irritation: if the oil comes into contact with the ocular mucosa, it can cause burning, tearing, redness, or a temporary blurring sensation. Some people also develop allergic reactions or skin sensitizations, due to an individual intolerance to the ricinoleate molecule.

Its dense and sticky consistency makes it difficult to dose and distribute evenly, increasing the risk of it getting into the eyes or leaving an annoying film on the lash line. Furthermore, applied in excess, it can make eyelashes heavier, promoting their shedding rather than protecting them.

It should not be forgotten that castor oil is also a highly occlusive product: it creates a film on the surface of the hair that prevents perspiration. In practice, the eyelashes "do not breathe" and risk weakening over time, especially if exposed to the sun immediately after application. In this case, a small "greenhouse effect" can literally be created, which dehydrates instead of nourishing.

For those who want to nourish and protect eyelashes and eyebrows safely, there are more modern and effective alternatives. The InLei® aftercare collection focuses precisely on this: providing aftercare treatments based on advanced molecules, which hydrate, strengthen, and shine the hair without weighing it down or irritating the skin. All products in the line are dedicated to the care and beauty of eyelashes and eyebrows, to combine the delicacy of tradition with the strength of cosmetic innovation - both in household products and in professional lines.

Is it worth using castor oil for eyelashes and eyebrows?

After all we've said about castor oil, it's natural to wonder if it's really worth using it for eyelashes and eyebrows. The truth is that a lot depends on expectations: it's not a miracle ingredient, but it can offer some benefits if used consistently and correctly.

If you think castor oil can make new eyelashes or eyebrows grow, the answer is no. But if you consider it a natural emollient, useful for making hair softer and more resistant to breakage, then yes, it can make sense, provided you use it with extreme caution and consistency.

The problem is that castor oil requires very long times and a consistency almost impossible to maintain. We're not talking about weeks, but about months of daily applications to notice any small improvement.
In an era where beauty routines must reconcile with increasingly hectic rhythms, it is difficult to consider it a truly effective or practical remedy.

Moreover, its heavy consistency makes it incompatible with makeup or eyelash extension products: it compromises the hold of the glue and leaves the area shiny and greasy. Another critical point is its occlusive nature: it traps heat and moisture, risking damage to the hairs and, in case of sun exposure, overheating them excessively.

For all these reasons, we advise you to opt for the alternatives that cosmetic research makes available to us. We are convinced that keeping eyelashes and eyebrows healthy and strong by using intelligently processed natural ingredients is definitely the best solution. That's why all the treatments you find on our lashINbrow website represent a new generation of cosmetics: lighter, faster in results, and, above all, designed to respect hair physiology.

Because authentic beauty always comes from a balance: between nature and research, between daily care and real results!