Pipette with essential liquid, closeup

Microbial deterioration (growth of mould, yeast, and bacteria) is an important aspect to consider when homemade cosmetics contain water. This deterioration occurs especially in cosmetics and personal hygiene products that have been made with an aqueous phase.

Creams and products that only contain oils need just an antioxidant to prevent their ranting and prolong their shelf life. As you know, most of us use a few drops of vitamin E to preserve them.


Choosing the right packaging also affects the shelf life of the product. For creams and fine liquids, it is convenient to use a dispenser instead of a jar of cream to avoid frequently touching it with your fingers. It is advisable to use glass containers, if possible dark, that avoid sunlight and sudden changes in temperature. If we use a jar to pack our cream, we can also use a spatula to avoid touching it with our fingers.

And, in any case, if we are not going to dedicate ourselves to selling our products, surely, we can keep them in the fridge for a few weeks or prepare a minimum amount that we can use in a few days. When we make homemade natural cosmetics, in many cases, it is not necessary that we use preservatives of any kind.



In a previous post (homemade-natural-cosmetics-and-organic-cosmetics) we talked about the importance of using emulsifiers as natural as possible so that our creams have the maximum properties for the skin and are as assimilable as possible, even in the case of atopic skin.

The second pillar that makes a homemade cream a stable high-end cosmetic is the use of suitable preservatives as natural as possible.

Keep in mind that the best brands of natural cosmetics such as Weleda or Dra Hauschka do not use synthetic preservatives and produce mostly products that are biodegradable.

According to Weleda: “More than 80% of all natural substances used by Weleda in cosmetics come from controlled organic crops. Weleda strives to increase this percentage each year by partnering with certified organic producers or implementing new organic and biodynamic farming projects. We consciously refrain from using synthetic dyes, fragrances and preservatives.”

We have to think that all preservatives, both those used in cosmetics, as well as those used in processed food, as well as those used to preserve our personal hygiene products, are biocides* by nature. *Biocides are substances that due to their physical, chemical or biological properties with antimicrobial effect can neutralize, control and / or reduce the pathogenic bacterial load.

Preservatives have to fulfil the specific function for which they have been designed, which is to preserve our creams from fungi, moulds and bacteria that reproduce over time in all creams and personal hygiene products that contain water.

For these same reasons, preservatives are always a controversial ingredient in any natural health approach. They give problems with processed food, and also with processed cosmetics, since they are the first substances, along with synthetic perfumes, susceptible to causing allergies and intolerances.

People with intolerance to processed food have digestion problems, flatulence or even irritable bowel, and people with intolerance to industrial cosmetics get eczema, redness and their skin is left cardboard after the use of this type of creams.

A luxury that those of us who make natural cosmetics enjoy is being able to prepare creams without preservatives or with selective preservatives*. *Next, we will try to explain what a selective biocidal substance is.

And, without a doubt, that, and the quality of the natural ingredients, is what makes the difference between homemade natural cosmetics and industrial cosmetics.

Even herbalist cosmetics are not always reliable, because, although some brands are saved more than others since they use selective preservatives and natural ingredients (Weleda, Dra Hauschka, etc … this is not always the case.




Life expectancy worldwide jumped during the second half of the nineteenth century, coinciding with Louis Pasteur’s germ theory of infections. Thanks to it, it was shown that there were infectious diseases that were caused by microorganisms and, with this knowledge, our ability to fight them increased. We have improved our hygiene habits and developed medicines and biocidal products that help us fight bacteria, viruses, fungi and other pathogens.

Therefore, nowadays, biocidal products are part of our daily lives. When we enter a pool or use tap water, we want it to be clean and free of harmful microorganisms. For that it is necessary to use biocides and, in these cases, the most common and widely used biocide is none other than chlorine.

Other types of biocides in everyday use are hydroalcoholic gels, insect repellents, water purification tablets or even more innovative products such as textiles that reduce the smell of sweat.

Biocidal products are necessary to control organisms dangerous to our health, but that does not mean that they are products that, used without control, entail serious risks. In many cases, it will not be necessary to use biocides and we may even have more recommended alternatives. This is something that we must take into account, for example, in the case of hydroalcoholic gel. If we get used to disinfecting our hands continuously with this gel, we will end up wearing down the barrier function of the skin. For this reason, it is recommended to wash your hands with soap and water whenever you have the possibility, instead of always using hydroalcoholic gel.

And it is that the safe use of biocides goes through not making excessive use since using them indeterminately and in large quantities can cause bacteria to develop resistance to them, which would lose their effectiveness.

This thing that the zschimmer-schwarz page explains with the hydroalcoholic gel, is something similar to what is happening and happening with antibiotics, which are the biocidal substances that are used in medicine to fight infections. That’s why doctors too, lately, always advise us not to use them indiscriminately.

In short, as all experts explain today, when using a biocide, you must always make sure that it is used correctly.

 This also applies, therefore, to preservative biocidal substances used to preserve natural cosmetics. And at this point it would be important to understand, therefore, the difference between selective biocidal products and less selective biocidal products.



Although this concept is applied in agronomy to differentiate between biocidal substances that fight different pests, in medicine the term makes use of the ability of a biocidal substance to respect good bacteria by exterminating only bad or pathogenic bacteria.

And this is what today has led to the rise of herbalism, aromatherapy and natural cosmetics. Whether we like it more or we like it less, it seems that biocidal substances capable of discriminating between good bacteria in an organism against bad bacteria, usually are of natural origin.

It is for this reason that many experiments are being done lately with essential oils for their ability to selectively fight infections that conventional antibiotics have stopped fighting since bacteria have become resistant to them.

And, apparently, conventional antibiotics wipe out all kinds of bacteria leaving the body unprotected, on the other hand, the antibiotic of natural origin (plant, essential oil, etc.) since it is formed by a synergy of multiple different organic compounds that are usually more difficult to identify by bacteria, provides greater effectiveness, as well as a greater degree of respect for the treated organism.

It has been seen that ginger fights some harmful stomach and intestinal bacteria, but respects good bacteria, favouring digestion. The same happens with raw garlic or onion. Or Neem oil, which fights harmful pests of crops respecting plants, and which, when used in a medicinal context, respects, for example, the good bacteria in our oral cavity or our skin if used as a treatment oil against psoriasis.

Therefore, a selective biocidal agent, by definition, would be that substance with the capacity to fight pathogens while respecting the healthy bacterial environment of an organism.

That is why a selective biocidal substance, for example, a preservative that we sometimes need to use in natural cosmetics, can preserve the shelf life of our product without destroying the natural protective layer of our skin that acts as a barrier against pathogenic organisms.



Another very important issue to consider is the bioavailability of a substance. It happens with the substances synthesized in a laboratory that, many times, the body can not recognize and assimilate them with which they become a toxic that the body has to eliminate with effort.

This was the case I raised in a previous article about fluoride being artificially added to toothpastes. When fluoride is of natural origin, it does not usually present a bioavailability problem, which can be beneficial in the prevention and treatment of caries.



It is the same reason why we protest against the “natural” cosmetics loaded with synthetic substances that some pages advertise.

Example of psoriasis treatment cream recipe found on the internet:

15% calendula oleate

5% shea butter

9% Cayenne Pepper Oleate

8% Black Cumin Oil (which works as a simile of cortisone)

2% Beeswax

4% of Olivem 1000

7% Glyceryl Monostearate

1% Cetyl Alcohol

14% Sandalwood Hydrolate which is anti-inflammatory

14% Roman Chamomile Hydrolate

5% Aloe vera

0.5% Allantoin, which is also anti-inflammatory

6% Urea, which is keratolytic

1% Retinol Palmitate (vit. A)

5% willow bark extract, which is antimicrobial and keratolytic.

Plus 1% vitamin E and 1% of COSGARD preservative

0.1% blue chamomile C02 extract

And the following essential oils in the proportion of 0.75% each:

Black spruce (cortisone simile, dermatitis), katafray (antipruritus, antihistamine), incense, and peppermint (anaesthetic, antipruritic) …

Replaceable by lavender, carrot, blue chamomile, manuka, copaiba…



This recipe that at first glance looks very good and very complete, if you look closely, you will appreciate that it can be a bomb for a skin affected by psoriasis.

First, because of the huge number of different components it carries that are likely to cause incompatibilities between them when, what is sought, precisely more in a treatment cream, is to create synergies.

Then, to be able to control all this water that they have put in, of course, you have to add 1% of Cosgard. Then think of all the synthetic active ingredients such as urea, glyceryl monostearate, synthetic allantoin, when the comfrey plant contains it naturally …

And the pinnacle, the amount and variety of essential oils that the recipe carries. Yes, they are all very good at treating psoriasis, but in a harmonic synergy of a few and in a much lower dose. Experts even recommend not using essential oils in products for this type of delicate skin. As we always say, essential oils are very powerful.

Remember that the soaps designed for delicate skin (with dermatitis, psoriasis, etc.) are made even without surfactants to be softer. They are known as “soap-free soaps”.

Don’t get carried away by this kind of misleading advertising, a “paella-recipe” is not better because we put more ingredients in it, but because we know how to combine a few, the traditional ones, in a harmonious way. And a cosmetic recipe is something like that.

A cream for a person affected by psoriasis can be a simple quality vegetable oil, which does not need any preservative, combined with a few drops of myrrh essential oil.

And I’m not saying that, but John O.A. Pagano, author of the book: “Healing Psoriasis” from Turner Publishing Company.

The most important thing in this type of skin is that it is hydrated and nourished in order to avoid inflammation and flaking and this, always, in a very gentle way so that it does not irritate anymore. Rubbing, simply with natural Neem oil, already usually provides great relief to this type of skin.



However, a substance or compound does not have to be harmful in itself simply because it has been synthesized in a laboratory. This is not always the case. We have the example of GSE (grapefruit seed extract) that we have also seen in a previous post.

What it is about is that, although it has been synthesized in a laboratory, the result is bioavailable, that is, that our body does not recognize it as a toxic that cannot metabolize.

Naturally, this is why, on the pages of cosmetic ingredients for sensitive skin, it can often be read that their products are based on natural or naturally identical ingredients: “Based on natural and nature-identical ingredients”. Zinc oxide, for example, which most of us use to provide our natural creams with a photoprotection factor is usually a product synthesized in a laboratory by copying the natural substance.

Logically, cosmetic manufacturers are not stupid and know very well that natural products have greater bioavailability, greater assimilation and better tolerance in all skin types, including the most sensitive, what happens is that “manufacturing natural” is very expensive and difficult to carry to term, and that is the reason why they try to sell us the product with green camouflage strategies or “greenwashing”.



As we mentioned before, if you are going to make homemade natural cosmetics do not use preservatives (use the fridge and prepare small doses of product). And if it is not possible, try always to use preservatives for your homemade preparations as naturals as possible, or, at least, naturally bioavailable that cause less irritation in sensitive skin, which allows the whole of your product to be absorbed and better assimilated.

For example, in front of the famous COSGARD or Geogard (both are the same) that everyone uses happily; why not use LEUCIDAL?

An expert website on ingredients for natural cosmetics

compares Leucidal SF Compleet with Cosgard and Rokonsal and Leucidal, the truth is, the comparison comes to the fore.


LEUCIDAL SF Compleet: Preservative of natural origin produced by biotechnology and certified as organic by BDIH and Natrue. Whose INCI is: Lactobacillus ferment, Lactobacillus, Cocos Nucifera (coconut) fruit extract.

Description: Leucidal SF Complete stands out for its good compatibility with the skin in cosmetics. It is a broad-spectrum preservative and protects against yeasts, molds and bacteria. Therefore, no additional preservative is necessary. It is a clear liquid that, unlike Rokonsal and Cosgard, dissolves very easily in water. Used in doses of 2-4%

Leucidal SF Complete combines the antibacterial activity of lactobacillus ferment with the antifungal activity of AMTicide Coconut (derived from Coconut).

Its applicability is comparable to that of Rokonsal and Cosgard, however, Leucidal Compleet is effective in a wider range of pH values; namely 3-8 (rather than a maximum of 5 and 7) and more soluble in water.

If you do not find the LEUCIDAL Compleet, the simple LEUCIDAL is also very interesting and even more appropriate for the most sensitive skin. INCI: Leuconostoc/Radish Root Ferment Filtrate. Of course, its ability to extend the useful life of the product is somewhat less and would be reduced to a maximum of three months. It is a product of 100% natural origin produced by the fermentation of radishes with the bacteria Leuconostoc Kimchii (a genus of lactic acid bacteria). It is a preservative very well tolerated by the skin that contains peptides with antibacterial properties that at the same time have shown moisturizing and conditioning properties on the skin.

Dosage: 2%-4% for a conservation of 2 to 3 months in optimal conditions of elaboration and conservation. One gram of Leucidal corresponds to approximately 22 drops.

Use: With Leucidal Liquid we can preserve all kinds of homemade cosmetics that contain aqueous phase such as gels, emulsions (lotions, creams, milks), shampoos, shower gels, sprays, etc. We add it to the finished product and cooled and mix/stir well to homogenize. Leucidal Liquid acts in the pH range of 3 to 8 and is stable at temperatures up to 70°C.

In the shop it is also possible to find a new preservative of vegetable origin, DERMORGANICS 1388, whose INCI is: Glycerine, Aqua, Sodium Levulinate, Sodium Anisate.

This preservative meets the ECOCERT criteria (100% natural and 46% organic/organic) and keeps homemade products for a maximum of three months. In addition, its components are of vegetable origin: star anise, sugar cane, soy / corn and vegetable glycerine.

USES: It can be used both in oil-in-water emulsions (o/w) and in water-in-oil (w/o) or in hydroalcoholic bases. It can be introduced at the beginning of the aqueous phase or at the end (there is no problem with the temperature) although it is recommended that the pH of the formulation is between 4 and 5.5. It is dosed between 2-4% and, like Leucidal, does not usually cause irritations or allergies.

In the same vein, we will avoid synthetic perfumes, as well as the excessive use of essential oils.  The danger with essential oils is not that they are toxic, since they are totally natural products, but their high biocidal potency that can cause irritation to the skin if you do not know how to adjust the dose correctly. As they are very potent, generally, the doses have to be very low.



Along with the well-known Cosgard, we find other commercial preservatives based on different chemical mixtures. Among them, Rokonsal, Sharomix, Potassium Sorbate, which is also used to preserve processed food from fungi and molds and which, normally, requires the addition of another    complementary bactericidal preservative.

Rokonsal and Sharomix consist, like Cosgard, of mixtures in different proportions of benzoic acid and benzyl alcohol. Sometimes with the addition of sorbic or dehydroacetic acid.

GEOGARD or COSGARD: This preservative that we talked about earlier is composed of benzyl alcohol and dihydroacetic acid. Geogard and Cosgard are the trade names for this preservative, so it will be listed on the label as benzyl alcohol and dihydroacetic acid. It is a synergistic mixture of an organic acid and alcohol. The two ingredients are organic compounds accepted for use in natural and organic cosmetics and approved by Ecocert. This preservative system has a wide range of potential uses, is effective in products with a pH of 2-7 and does not include parabens, formaldehyde or isothiazolone. However, benzyl alcohol has been proven to irritate infants and people with atopic skin.

BALSAM OF PERU (Myroxylon balsamum) which is an extraction in alcohol of the resin of this tree with its properties. It is normally used as a perfume fixator, but it can also act as a preservative given its significant amount of acids and phenolic esters: benzyl benzoate (44.85%), benzyl cinnamate (28.25%), cinnamic acid (9.27%), benzoic acid (8.10%) …



BENZOIN RESIN EXTRACT: Normally, it is also an alcohol extraction of the resin of the benzoin tree. Its benzoic acid content is greater than 60% and also contains benzyl benzoate in a percentage not less than 3%. Both preservatives also have a pleasant smell of very characteristic “vanilla”. These two natural preservatives would be something of a natural version of Cosgard due to its high content of natural benzoic acid.



NATICIDE OR PLANTASERV Q: Naticide or Plantaserv Q are the trade names of this natural preservative. You can find it on labels like Fragrance or Parfum. Generally, these terms are red flags, however, Naticide is a safe compound that is used in natural and organic cosmetics. You may be able to identify it by its sweet vanilla and almond aroma. This preservative is plant-based and has a wide range of uses. It is effective in preventing the growth of various yeasts and moulds in products with a pH of 4-9.

GSE, grapefruit seed extract: This product, which was not originally designed as a cosmetic preservative, but as an antibiotic treatment of the flus and colds that many naturopaths use to fight viruses on a general level, has become popular as a cosmetic preservative for its good dermal tolerance and its low probability of producing irritations.

This preservative has good antibacterial efficacy, but is less effective on yeasts and moulds. The truth is that it is a very useful preservative when it comes to preserving all cosmetic preparations that contain an aqueous phase (without xanthan gum) and can be complemented with a few drops of an antifungal EO, such as tea tree, with which its conservation capacity is considerably prolonged. For example, it preserves homemade aloe vera gel very naturally, also homemade water-based lotions and hydrolats. This preservative allows to extend the shelf life of these products for at least a month and something more combined with the EO of tea tree.

However, it is not a very suitable preservative when we want to preserve creams emulsified with Ester de sucre because it tends to destabilize them. Likewise, it destabilizes emulsified creams with the help of xanthan gum and even tends to separate the phases of preparations with Olivem 1000.

COLLOIDAL SILVER: You will find it as an exceptional component in creams for the treatment of atopic skin. However, it is not usually among the preservatives available on the pages of ingredient suppliers for natural cosmetics.



Silver is a broad-spectrum antimicrobial agent whose efficacy has been proven against the microorganisms that surround us today such as E. coli, Legionella, Pseudomonas, Salmonella, S. aureus, A. niger, among others. Colloidal silver prevents the growth of bacteria, moulds and fungi, as well as other microorganisms. The use of silver compounds for skin care has COSMOS and ECOCERT certifications and, for this reason, colloidal, metallic or ionic silver is used in countless cosmetic applications to maintain and protect the good condition of the skin, as well as preservative avoiding the use of parabens.

Why not use it too when we want to preserve our creams?

Dosage: Between 0.5 -1% of the total product if it is colloidal silver. And we would add it in the final phase of the mixture so that it would not be affected by the temperature.


NATURAL ALCOHOL OR ETHANOL: The unnatured alcohol, which is used to make tinctures, is a natural preservative especially suitable for our shampoos and shower gels, as well as for all our lotions and creams taking into account that the degree of protection of this natural preservative is not the same as that of a preservative specifically designed for this purpose such as Leucidal, for example.


However, many people macerate plants such as horsetail or willow bark extract in this alcohol greatly lengthening its usefulness as a preservative. For example, it is possible to macerate dry horsetail for about 2 or 3 weeks in alcohol stirring from time to time. Then, we filter it and obtain this interesting natural preservative.

VEGETABLE SALICYLIC ACID: Macerating willow bark extract in ethanol is even more effective as a preservative because the willow tree (salix alba) contains natural salicins. That is, natural vegetable salicylic acid. This natural preservative is therefore very effective against bacteria, but less against yeasts and moulds, to prolong the shelf life it is recommended to combine it with another preservative, which could be a few drops of an antifungal essential oil such as tea tree or palmarosa.

This preservative based on a natural maceration of willow bark in ethanol is not irritating or sensitizing and improves skin cell renewal.

The willow tree has historically been prized for its analgesic, antiseptic, astringent, antipyretic and anti-inflammatory properties. Current studies have proven that the natural salicylic acid in this willow extract promotes cell renewal much more than the synthetic salicylic acid used separately. The same was demonstrated in the case of antimicrobial properties. Surely is it due to its greater bioavailability?

Salicylic acid has a keratolytic action (“peeling” effect that stimulates cell renewal, soothes and softens the skin and prevents calluses) and, in addition, due to its astringents and antibacterial properties it helps regulate oily skin and is very appropriate for the care of skin with acne and blackhead spots. Therefore, this preservative is especially indicated to make cleansing products for the skin with impurities, anti-acne and anti-aging creams, and shampoos with anti-dandruff effect or for oily hair.



The preservative Naticide or Plantaserv Q is very mild and is supposed to be tolerated even by young children. It will keep our preparations for about 3 months. In homemade cosmetics it is dosed at 0.6%.

However, it has the disadvantage that it is scarcely soluble in purely aqueous media, thus causing a risk of irritation when used in aqueous gels or lotions.  Although, if mixed in an emulsion, it is not a problem. It is successfully used in creams, shampoos, lotions…

If you need a more stable preservative to preserve, for example, natural aloe vera gel or aqueous emulsions, then use the GSE as we mentioned before.

ESSENTIAL OILS: Strictly speaking, essential oils are not preservatives. However, some have significant antibacterial or fungicidal power, which can improve the shelf life of our cosmetics. We shouldn’t rely on them as preservatives exclusively because it won’t work, or at least not for long. However, sometimes they can act by enhancing the action of other preservatives as we mentioned in the example of GSE.

FOR EXAMPLE; To enhance the bactericidal action of a preservative, we can resort to a drop of the following essential oils with bactericidal capabilities: lavender, tea tree, noble laurel or even eucalyptus radiata or thyme. To enhance the fungicidal effect, we can resort to fungicidal essential oils such as tea tree, pink geranium, palmarosa or even rosewood or hô.

Remember, as we already know, that all these essential oils should be avoided in children under three years of age and some of them also in pregnant women.




It is to elaborate cosmetic alternatives “without water” that do not need biocides for their maintenance.

For example:

Use cold-saponified soap bars as an alternative to shower gels, which also do not need packaging and are more sustainable than products packaged in plastic bottles.

Toothpastes formulated without water.

Use a hydrolate as a purifying tonic substitute for a micellar water loaded with preservatives.

Make-up removers formulated without water, based on oils.

Use a BB-cream formulated without water like the one we offered in a previous post.

Use oil serums instead of facial creams.

Use solid shampoos that also do not need preservatives.

Many of the products you can self-make (deodorants, gels, soaps) can be kept for weeks with a few drops of powerful essential oils such as lemon, rosemary, lavender … and think that you can also combine them intelligently to enhance their effects. For example, lemon essential oil, which is antibacterial, with clove EO, which is antifungal…

As you can see, many things are replaceable. Do not think that sometimes I do not also fall into the temptation of homemade creams and lotions that contain water, but, in that case, I try to use natural preservatives that do not leave my skin like cardboard.

Think that all the non-biodegradable preservatives that you avoid are also avoided to the aquatic environment that is where all the substances we consume end up.



In short, no preservative is completely harmless to the skin and body. None of them is harmless due to their biocidal capabilities, more or less selective, but we must also not forget that dosing is very important.

It is the dose that produces the poison as has always been said throughout the history of medicine. Many substances that in small doses can be beneficial can be hugely toxic in larger doses.





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