Limitations of use and contraindications

Safety, toxicity and contraindications

The vast majority of essential oils are incredibly easy to use.

Nevertheless, some of them require a little bit more of attention but are no problem in the end, if used cautiously.

Lastly, a few of them (rarely) are only to be used by professionals.

However, all of them (no exception at all) can be used for their olfactory and energetic properties by diffusing, spraying or carrying them in your pocket.
This makes any plant and any oil available for a happily easy use.

The different ways to use essential oils are described under "Use of essential oils".


Everything is nature is both toxic and beneficial : it is only a matter of dosage

A too high dose of anything on Earth (even water, salt or carrots) taken repeatedly may cause serious issues, even death on some rare occasions.

However, a little dose of anything, even toxic plants, is absolutely harmless. You only need to know about these doses and use them accordingly.

The toxicity point of the easiest essential oils lies below that of kitchen salt ! This means you can ingest a larger amount of this oil before noticing any problematic dysfunctionn in your body than you can with salt.

The few drops usually prescribed for traditional minor affections are completely non-toxic, for essential oils known to bear no contraindications within physiological dosage.

Physiological dosage
means the doses commonly prescribed by professionals.
It is generally between 1 to 10 drops a day for classic essential oils (non-toxic) depending on the oils.
Again : depending on which oil you use of course.
and the way to take it (orally, on the skin), depending on the patient, the affection etc.

It is clear that essential oils are most often prescribed in a preparation where they are diluted.
A few essential oils may be taken pure, licked off the back of the hand for example. This can only be done when you know the patients and their potential reactions.

For most people, it is a pleasant way to take oils, but for more sensitive ones, the power of oils may be uncomfortable.

Basic rules


NEVER pour essential oils into your eyes.

If it accidentally happens, rinse abundantly with carrier oil (any oil you use to cook is suitable) and call a doctor or pharmacist immediatly.


Genital mucous membranes

NEVER use essential oils on genitals.

If it accidently happens, rinse abundantly with carrier oil (any oil you use to cook is suitable). 



NEVER use essential oils in ears.

If it accidently happens, rinse abundantly with carrier oil (any oil you use to cook is suitable).


Accidental ingestion

In case of accidental ingestion of a contraindicated essential oil,
do not try to or make one vomit.
drink a large amount of carrier oil (or of excipient, milk or vegetal milk).

The person may then vomit and this is a good thing : the essential oil will come out without causing even more trouble in the oesophagus as it will then be diluted.

The toxicological threat due to the oil being continually absorbed is aside.

Then call a doctor, a pharmacist, or any emergency number (911 (worldwide), 112 (UK), 000 (Australia), 111 (New-Zealand) etc.)



Pregnant women

All essential oils known to be at least a little bie toxic are absolutely contraindicated for pregnant women.

Even though no problem has been reported so far within physiological dosage, it is preferable to keep safer.

Though the limit is very tiny, the therapeutic "comfort zone" is often quite large with essential oils.

Using essential oils on a pregnant woman can only be done by a well- trained professional.


Breastfeeding women

Very few essential oils contain toxic molecules which may transfer into breast milk.

For the oils that do, this is written in the description.

You can be completely confident with the rest of them.

Only a well-trained professional can use/prescribe essential oils on/to breastfeeding women. 



the first thing to do is to adapt the dosage according to the child's weight and height and also to his own sensitivity.

Children have a fast metabolism which differs slightly from that of adults.
For more safety reasons, let's not use any toxic essential oil on children.
Only a well-trained professional can use/prescribe essential oils on/to a young child.

A dropper is the best security ever for children: please never take it off. If they accidentally take a bottle of essential oil and open it, they will quickly stop after one or two drops, even only because of its... powerful taste and avoid any potentially harmful accident.


Epileptic people

Some essential oil contain epileptogenic molecules if taken at high dosage (some monoterpenic ketones).

It is safer never to use them on epileptic people,
as a risk of causing epileptic crisis exists if the oil is taken repeatedly.

Only a well-trained professional can use/prescribe essential oils on/for epileptic people.



There is no contraindication about using pure essential oils on wounds.

On the contrary : anti-infective essential oils (Palmarosa for example), healing ones (Frankincense for example), and oils which stimulate cells regeneration are to be used pure for very efficient effets.

Dermocaustic essential oils should not be used on wounds.

Essential oils should not be diluted in carrier oil, creams etc. if used on a wound. Indeed, this tends to hinder the healing process.


Toxicity vocabulary

You will find here the definition of the words used on this website as well as in most books about aromatherapy.



This word means :
« sensitive to light ».
Indeed, some molecules like furanocoumarines are photosensitising.
These molecules react to ultraviolet rays.
Hence, they may cause rapid sunbruns or agravate existing sunburns. They may also stain the skin for a long time before they are completely eliminated by the body.

This happens when you expose the "oiled up" part of your body to the sun.
Photosensitisation may last up to 12 hours.
It is strongly advised not to go out in the sun or to the tanning salon for a whole day after applying photosensitising oils, even if you wash it off beforehands.

However, this does not cause toxicity of any kind afterwards.

Here are a few basic rules :
  • La photosensitisation lasts up to 12 hours.
  • It reaches its maximum an hour after the application.
  • Dilution in carrier oil or cream clearly extends this period of photosensitisation (i.e if you use such oils in you night cream, you may consider your morning shower as the start of the 12-hour photosensitisation period)
  • Washing the oil off, even with soap, has no effect whatsoever.
  • This is only valid for the area where the oil has actually been put on.
  • If you apply photosensitising oils on yourself with your hand and then touch any other part of your body with the same hand, you may consider all the those parts as photosensitive.
  • Oral ingestion theoretically also leads to photosensitisation. However ,this is not relevant at all. We may consider that there will be no photosensitisation within physiological dosage. Exposure to sun requires to put suncream on to avoid sunburns anyway.
  • The only efficient protection after putting on photosensitising essential oils is to wear clothes.
To sum up :
  • Choose another essential oils with similar properties if you plan to go out in the sun afterwards.
  • Choose another way to use it if possible (diffusing or spraying it instead for energetic results for example)
  • Wait for 12 hours or wear a T-shirt if you need to go out in the sun.



Many plants are abortifacient.
However, no abortion has been reported while using essential oils.
Juniperus sabina essential oil is no longer produced due to its true abortifacient effects.
Rute graveolens is a very abortifcient plant and a pregnant woman should REALLY avoid using it (it is highly toxic anyway).

The limit for an oil to be abortifacient is far beyond its limit for toxicity.
They are therefore more likely to harm the future mother rather than to chase the baby away.

In any case, using an abortifacient essential oil on a pregnant woman is NEVER compulsory and there is no obligation to prescribe or ingest them. 

Only a well-trained professional is likely to use or prescribe essential oils on/to pregnant women..



« Which boosts the uterus ».

A uterotonic essential oil may reinforce uterine contractions.

They are blessed as support for labour, it is therefore preferable not to use them during pregnancy.



some essential oils may indeed be neurotoxic.

This means they can harm the nervous system.

This applies to monoterpenic ketones.
Their neurotoxicity acts through lysis of the myelin sheath of axons and dendrites.
As they are also liposoluble, they particularly like the central nervous system in body fat where they like to accumulate.

So they are not to be used on epileptic people, prgnant women, young children and never to be used repeatedly during more than 3 weeks. 



Thymol and carvacrol present in certain essential oils are known to be highly hepatotoxic (toxic for the liver).

They are to be avoided on pregnant women, children and people with known liver issues (hepatitis, cirrhosis, glutathione depletion etc.)

You will find more information in the description of every essential oil that contains these molecules.


Any other behaviour to have in case of known potential toxicity of an essential oil is written in the descriptions.

So do not worry!

Oils with no known contraindications within physiological dosage are extremely easy to use are often breathtakingly efficient.
If you think you need a so-called toxic oil, you should see a professional first, listen to and follow his professional opinion.

Recipes or dosages for each oil or disease will not be given here.
Using essential oils therapeutically can only be done if you know aromatherapy in a professional way.
There are courses and books for that.
Some courses and some books are available here.

A professional practitioner adapts the doses according to his knowledge of the human body, aromatherapy and of his patient as a whole.

Call center for toxicology in Switzerland (Zurich): 044 251 51 51

Essential Oils

Agatophylle Agatophylle leaves Ajowan Ajwain All-spice Allspice Angelica Arabian jasmine Archangel Balsam fir Basil (exotic) Bay laurel Bergamot Bigaradier feuilles Black Pepper Black pepper Black spruce Blue ginger Camphor cineol CT leaves 1,8-cineole (Madagascar) Cananga Cane Cardamom Cedar (Atlas) Celery Ceylan citronella Chamomile Chamomile (roman) Chamomile(roman) Cilanthro (leaves) Cinnamon Cinnamon (bark) Cinnamon (leaves) Cinnamon bark Cinnamon leaves Citronella Clove Clove bud Clove leaf Cochingrass Common sage Coriander Cumin Cupressus Curcuma Curry leaf Curry plant Curry tree Cuscusgrass Cypress Davana Dill East-indian Lemongrass Eucalyptus radiata Everlasting Exotic basil Fennel Fir Fir (Balsam) Fir (balsam) Flag Frankincense Frankincense (salai) Galanga Galangal Garden Angelica Garden dill Geranium Ginger Gingergrass Grapefruit Greater galanga Green Mandarin Green Pepper Green cardamom Green pepper Grey eucalyptus Helichrysum angustifolium Helichrysum italicum Holy basil Ilang-ilang Indian Basil Indian Frankincense Indian wintergreen Jamanatsi Jasmine Jasmine (arabian) Jasmine (royal) Jeera safed Jessamine Juniper berries Khus-khus Lavender Lemon Lemon (yellow) Lemongrass Limetta Macassar-oil plant Malabargrass Mandarin Mediterranean sweet lemon Mulilam Muskroot Myrrh Nard Nardin Narrow leaf eucalyptus Narrow leaved peppermint Norway pine Officinal lavender Officinal rosemary Orange Orange (sweet) Orange bergamot Orange peel Oranger amer feuilles Oregano Palmarosa Parsley Patchouli Pelargonium Pepper Peppermint Petitgrain Bigarade Pimento Pine Pine (Norway) Pomelo Ravensara Ravintsara Roman chamomile Rose geranium Rose pelargonium Rosemary Rosemary borneon Rosha grass Royal jasmine Sacred basil Sage Salai Frankincense Salvia Sambac Scotch pine Shaddock Spanish jasmine Spearmint Spearmint Spikenard Spruce Sweet cane Sweet celery Sweet fennel Sweet flag Sweet lemon Sweet lime Sweet limetta Sweet orange Tea tree Tea tree m.a. Thai galangal Thai ginger Thyme Thyme (thymol) Tropical Basil True lavender Tulsi Turmeric Turmeric (aromatica) Turmeric (longa) Valerian Vanilla Vetiver White Pepper White cumin White pepper Wild marjoram Wintergreen Yellow lemon Ylang-ylang Zanthoxylum