Castile soap vs. Glycerin soap: What is the difference?

Some people think that castile soap is better than glycerin for sensitive skin, while others are convinced otherwise. But what are the differences between these two wonderful soaps, and which one should suit you best?

One popular difference between Castile and Glycerin soap it’s made from natural vegetable oil, like olive or lye, and sodium chloride (salt). Glycerin soaps are created using glycerin as its base ingredient instead. The former have higher concentrations in antioxidants such as vitamin E correspondingly affecting its moisturizing benefits on your skin when compared to the latter.

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Many people have strong opinions about Castile vs. glycerin soap for sensitive skin, but there isn’t a ton of information out there to help you decide between them. There’s a lot of misinformation online and just plain bad advice from fellow shoppers who don’t know what they’re talking about.

What is castile soap and glycerin soap?

Castile soap and glycerin soap are similar products, but they have different purposes. In this section, you will find accurate definitions of both products and their effects on your skin.

  1. Castile Soap

Castile soap is categorized as a versatile cleaner, and it is mostly made of vegetable oils. Its name comes from Castile, a region from Spain. The people from Castile used to use olive oil and sodium carbonate, but the recipe has evolved since the 16th century. Now more ingredients are added, such as plant-based oils.

It is worth noting that this soap type has remained free of animal fat throughout time. Therefore, it’s also one of the best options for vegans. It is also possible to find Castile soap in liquid or solid presentations.

  1. Glycerin Soap

Glycerin soap is based on glycerin or glycerol, which comes from plant-based oils as well. Glycerin can also come out as a result of fermentation in certain goods, such as wine or bread.

Many people prefer using glycerin soap because it is all-natural and gentle on sensitive skin. It doesn’t contain any other additive that may cause harm to the user, and similar to castile soap, it is a vegan-friendly option.

Glycerin soap is also recommended to treat certain skin-related conditions, such as acne and dry skin. Furthermore, it is non-greasy, which can be beneficial for people with oily skin.

What is the main difference between Castile and glycerin soap?

The main difference between Castile soap and glycerin soap is their structure.

First, we have Castile soap, which is traditionally made with olive oil and sodium hydroxide. If you prefer the liquid presentation, you can replace the sodium hydroxide with potassium hydroxide. This soap is hugely versatile and can be used for multiple purposes, including cleaning wounds and as a face wash. Some people even utilize it as a shampoo, for instance.

Most people like using Castile soap due to the wide range of uses. It’s also worth noting that Castile soap is a cold process soap, traditionally speaking.

Contrary to what’s described above, glycerin soap is made of glycerol. This makes this soap more appropriate for sensitive skin as it has a moisturizing effect. Furthermore, glycerin soap is a byproduct of the soapmaking process. Most of the time, the glycerin is extracted from soap to be destined for different uses within the cosmetic industry.

Although Castile soap and glycerin soap undergo similar processes to achieve their final form, they’re destined for different purposes due to their structure.

Which is better, Castile or glycerin soap?

We can’t say that one option is better than the other as they’re both meant for different purposes. Therefore, it depends on what you’ll use the soap for. Both options have pretty much the same advantages. The only thing that changes is their structure.

Here we have the similarities between Castile and glycerin soap and how one is better than the other in certain aspects.

  • Both soaps are natural cleansers and hydrating. Therefore, you will be able to enjoy fresh, moisturized skin after using it. 
  • Castile and glycerin soap is suitable for sensitive skin. Since they’re made of natural ingredients, they’re safer to use. It’s also worth noting that they alleviate dry or irritated skin and are also helpful for oily or skins vulnerable to acne, among other skin conditions, like psoriasis.

As you can see, they’re pretty much the same product with a different structure and presentation. The only way we could say one is better than the other is if we consider allergies. One person can still enjoy glycerin soap’s benefits if they’re allergic to it, thanks to Castile soap, and vice versa.

Why would someone choose Castile or glycerin soap for their skin?

Here we will look at what benefits these two soaps have.

Castile soap has the following benefits:

Cleansing without Toxins: Most soaps use toxic sulfates to get that lather we’re all accustomed to, but castile soap doesn’t. Instead, it naturally cleanses and protects thanks to oleuropein – a compound with potent antibacterial effects!

It’s safe even for sensitive skin: The most important thing to know about Castile soaps is how they’re made. The simple plant oils combined with water create one of nature’s safest and most gentle cleansing agents, perfect for your skin!

Helps with acne-prone skin: The oils found in castile soap penetrate pores with antibacterial agents, helping clean your skin without drying it out. While we recommend avoiding acidic products because they can cause irritation and blemishes for some people who have sensitive or acne-prone skins; those using the product to balance their pH should be mindful of how much overcompensating will have a reactogenic effect on them than others when applied directly onto the face due to its high alkaline value (over 5).

Sooth’s dry, irritated skin: Olive oil is the perfect solution for dry, flaky skin. It helps moisturize and replenish your epidermal moisture level while not stripping away natural oils to give you that smooth look without any worries of being greasy or oily all day long.

Hydrates naturally: There are many benefits to using castile soap, including retaining all of its glycerin. This byproduct works to moisturize and soothe your skin as naturally as possible.

No more greasy pores: Olive oil, castile soap is great way to keep your skin clean and clear. It activates the natural shedding of dead cells while letting pores breathe with its moisturizing properties.

Natural protection: Olive oil is both an excellent moisturizer and antioxidant. It can be used as a facial mask to protect against skin cell degeneration, which will help keep wrinkles at bay and delay the aging process.

Glycerin soap has the following benefits:

Moisturizing: Glycerin is a natural humectant, and when used in soap, the glycerin will continue to attract moisture towards your skin. This means that soaps containing this ingredient are perfect for those who have dry or moisturized skins as they can provide extra hydration without feeling too greasy on top of providing all-around cleanliness.

Healing properties: Glycerin soap is the best cleanser for those suffering from dry skin conditions such as eczema and psoriasis. One study found that it can help heal cracks in just days when applied topically.

Gentle on skin: Glycerin is the go-to for gentle soaps because it has a neutral pH, meaning that it won’t irritate your skin or strip any moisture. So if you’re looking to keep things clean while also making sure not too much harm comes through on top of what’s coming off in water (fish oils), then this might be just right.

Ideal for dry skin conditions: Glycerin soap is the best for those with dry skin because it can attract moisture from your surroundings and bring that deep within to keep you happy, healthy & youthful.

Prevents damage to skin: Glycerin soaps without drying chemicals such as sodium lauryl sulfate can actually help prevent the skin from losing moisture. When we strip our skin’s natural oils, it becomes more susceptible to damage and breakouts by creating an environment with little or no protection against bacteria.

As explained in the sections above, both glycerin soap and Castile soap are suitable if what you want is a product that moisturizes your skin without causing any damage. Both soaps are free of harmful chemicals and are made of natural ingredients. Therefore, there is no better option for your skin than these two soaps.

However, please note that, unlike glycerin soap, Castile soap doesn’t normally cause secondary effects. Therefore, it is safe to use for most users as long as they’re not allergic to any of the materials used in the soapmaking process. 

Is Castile soap glycerin-based?

Castile soap does contain glycerin, as it grants it its moisturizing effects. However, the glycerol is obtained as a result of the soapmaking process as it is actually vegetable oil-based, be it coconut oil or olive oil, for instance. 

Glycerin is an essential component of Castile soap as it grants them the moisturizing, gentle effect it has on your skin. Still, Castile soap isn’t directly based on glycerin. You will still enjoy all the benefits associated with Glycerin soap, though. We can say that both options are synonymous with each other as they pretty much have the same benefits, but they have different disadvantages.

Pros and cons of using either Castile or glycerin soap

While Castile soap and glycerin soap have very similar effects, their structures are different. Therefore, you may experience different drawbacks unique to the option you’re utilizing. Here we’ll discuss the pros and cons associated with each soap type. This way, you can be sure of what option is most suitable for you.

  1. Castile Soap

Castile soap doesn’t have too many disadvantages that we can name, but it has plenty of benefits.


  • Castile soap can be utilized as a wound cleaner. You can utilize filtered drinking water or saline solution, especially in open fractures.
  • Besides being a natural cleaner, you can also use castile soap to make deodorant.
  • Castile soap works excellent as a face o body wash as it removes all the harmful bacteria from your skin. Thus, this fact makes it suitable for people that suffer from acne and other similar conditions. It is also helpful to exfoliate your skin.
  • Castile soap can be used as your hand soap. All you need to do is add two tablespoons of it to about 12oz of water and pour the mix into a soap dispenser.
  • If you don’t have shaving cream at home, you can use Castile soap instead. You can use carrier oil together with it to contribute to the moisturizing of your skin, too.
  • Castile soap is also an excellent makeup remover when you combine it with a carrier oil and witch hazel. All you need to do is mix all ingredients, all of them in equal quantities.


  • Castile soap will cause a reaction when used with hard water. It will then leave a white film behind after use. Therefore, if you’ll utilize castile soap at home, please consider installing a water softener. This same film can appear if you try to mix it with vinegar or lemon juice.
  • If you’ve dyed your hair, it’s not recommendable to use Castile soap on it as you will remove part of the color. It can be either an advantage or a disadvantage, though.
  1. Glycerin soap

Like Castile soap, there aren’t too many side effects associated with Glycerin soap. However, there are certain things to be aware of if you’ll utilize them.


  • Glycerin soap is hypoallergenic. Therefore, there is an extremely low risk of it causing any unpleasant side effects. However, it will lose this effect if you use fragrance oil and other additives on it though.
  • Thanks to glycerol, glycerin soap is excellent for moisturizing your skin. 
  • In the modern-day, animal fats are rarely used in the soapmaking process. People use plant-based glycerin to make their own soap most of the time. Therefore, it can be an excellent cruelty-free option.
  • It’s also worth noting that Glycerin Soap has a lower pH level, helping your skin retain its natural moisture.


  • Soap can dissolve pretty quickly if you leave it in water or if it absorbs too much moisture from the air. Therefore, it is recommendable to keep it in a moisture-free environment once you’ve finished using it.
  • If you choose to make glycerin soap, please note that although you’ll know every ingredient it contains, you will end up spending more money than you would by purchasing a whole batch of mass-produced glycerin soap.


As you can see, Castile soap and glycerin soap are the same product in different presentations. Due to their structure reacts differently to their environment, making them suitable for certain users over others. Still, both options are excellent for your skin as they will help you keep it as clean as possible throughout the day.

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