Understanding Essential Oil Dosages and Applications: A Practical Guide

If you’ve ever used essential oil for sleep in your wellness routine, you’ve probably asked yourself: “Am I using the right amount?” The answer isn't as simple as a one-size-fits-all approach. When it comes to applying essential oils, the dosage truly matters—and it's not just about how much you apply but how well your body absorbs it.

While we know that essential oils penetrate the skin and enter the bloodstream, the specifics are still being studied. How much oil actually makes it into your system? What factors influence absorption? Understanding these details is crucial to ensuring you're getting the most out of your oils.

Here, we’ll dive into the essentials of essential oil dosages, particularly through massage, and explore what factors influence how much oil gets absorbed into your skin.

How Much Is Just Right?

Before you start applying essential oils, it's good to remember that how much of the oil actually enters your bloodstream after a massage is still being researched. However, we do know that some essential oils do get through the skin’s outer layer, known as the stratum corneum. So, what factors affect how much is absorbed? Let’s break it down.

Key Factors Affecting Absorption

1. Total Quantity Applied: The more oil, cream, or other carriers you use, the greater the total essential oil absorbed.
2. Dilution Level: Essential oils are usually diluted in a “carrier” like a cream or vegetable oil, and the concentration of essential oil in that mix makes a difference. A 5% dilution will naturally deliver more essential oil than a 1% dilution.
3. Area of Application: Applying essential oils over a larger body area, like your back, allows for more absorption than focusing on a smaller area like your hands.

But that’s not all—absorption is also influenced by a few additional factors:

• Type of Essential Oil: Different oils have unique molecules, so each penetrates the skin at its own pace.
• Body Part: Skin thickness varies; for instance, the soles of the feet might absorb differently than the back.
• Carrier Oil or Base: The substance carrying your essential oil (like vegetable oil or gel) also plays a role.
• Skin Condition: If the skin is dry, broken, or inflamed, it may absorb oils differently than healthy, intact skin.
• Covering the Skin: Occluding (covering) the skin after applying oil can boost absorption.
• Timing Before Washing: Washing too soon can reduce the effectiveness, as some oil will wash away before it fully penetrates.

How to Calculate Essential Oil Dosages

When you’re working with essential oils, a little math can help you stay within safe and effective limits. Here’s a handy reference table for applying essential oils with different dilution percentages:

This table shows the amount of essential oil (in millilitres) you’d get based on the concentration and total carrier volume you’re using. For instance, if you’re using 10ml of a carrier at a 5% dilution, that’s 0.5ml of essential oil.

How Much of Essential Oils Are Absorbed Into the Skin?

When it comes to the absorption of essential oil wholesaler, it’s not an exact science — and that’s okay! The precise amount absorbed into the skin can vary based on several factors. But let’s explore some key insights from research and studies.

Studies on Absorption

Researchers have conducted some interesting studies on how much essential oil actually makes its way into our bloodstream. Here are a few examples:

1. The Lavender Oil Study
   In a study led by Prof. G. Buchbauer, lavender oil (2% concentration) mixed with peanut oil was massaged into a volunteer's abdomen for 10 minutes. The results showed that about 120 nanograms of linalool (the main compound in lavender) per millilitre of plasma was detected, peaking 20 minutes after application. This is quite a small amount, but when you consider the total blood volume (about 5 litres), it’s estimated that around 8% of the applied lavender oil dose made it into the bloodstream in just 20 minutes. Looking at the absorption over 90 minutes, it seems that about 10% of the total dose was absorbed.

(Graph representing the plasma concentration of linalool after the application of lavender oil)

1. Monkey Study on Absorption Rates
   A separate experiment involved applying essential oils to the skin of four monkeys using two different carriers: an emulsified cream and acetone. The study found absorption rates ranged from a low of 20% to a high of 70%, depending on the type of oil and carrier.
2. The 1940 Straehli Study
   A study by Straehli in 1940 looked into the absorption of various essential oils and their constituents. While it didn’t give exact figures on how much was absorbed, it helped establish that, in general, at least 10% of the applied dose can be absorbed, with absorption rates potentially much higher depending on the oil and other factors.

Factors That Influence How Much Oil Is Absorbed

Now that we have a rough idea of how much essential oil is absorbed let’s look at what influences that absorption:

• Skin Condition Matters
  If the skin is damaged, diseased, or inflamed (think eczema or burns), absorption rates can increase. This means if you’re using essential oils for therapeutic purposes on damaged skin, you need to be cautious with concentration and dosage.
• Carrier Oils and Viscosity
  The thickness of the oil matters. For instance, thicker oils like almond and olive oil tend to be absorbed more slowly compared to lighter oils like linseed oil. Emulsified creams (where the oil is broken into tiny droplets) or gels are often absorbed better than plain oils.
• Type of Essential Oil
  Lighter compounds, like C10 terpenes, are easier for your skin to absorb compared to heavier compounds like sesquiterpenes.
• Evaporation Is a Factor
  If you leave essential oils uncovered, much of the oil will evaporate into the air instead of being absorbed by the skin. Covering the skin with something like cling wrap can prevent evaporation and dramatically increase absorption.
• Skin Temperature
  Warm skin helps absorption. A study showed that increasing the skin’s temperature by just 10°C can significantly speed up the absorption rate of essential oils. So, applying essential oils after a warm shower or a quick massage will enhance how well they’re absorbed.
• Skin Hydration
  Hydrated skin absorbs oils more effectively. That’s why applying essential oils after a warm bath or shower, when your skin is moist and the pores are open, can be very beneficial.
• Covering the Skin for Increased Absorption
  If you apply essential oils and then cover the area with something like plastic wrap, the absorption rate can increase substantially. One study showed that fragrance compounds absorbed up to 75% when the skin was covered, compared to only 4% when left uncovered.
• The Role of Soaps and Detergents
  After washing your skin with soap, your skin’s permeability increases temporarily. This means your skin is more likely to absorb oils after you’ve showered or bathed, especially when the skin is hydrated and the circulation is increased.
• Emulsified Creams vs. Plain Oils
  Emulsified creams or gels tend to be absorbed better than pure carrier oils. The tiny droplets in emulsions make it easier for the oils to penetrate the skin’s surface.

Absorption into the Blood Circulation

Essential oil compounds are primarily absorbed through the skin, passing through the outermost layers of the stratum corneum and into the microcirculation of the dermis. However, there is a delay in absorption due to the structure of the epidermis. While the major absorption occurs within the first few hours of application, some compounds can remain "in reserve" in the skin for a prolonged period, gradually entering the bloodstream over the course of hours or even days. This slow release and absorption contribute to the generally lower systemic concentration of essential oils compared to other methods like oral ingestion, reducing the risk of acute toxicity.

• Time Lag: The compounds from essential oils take time to pass through the upper layers of the skin and the deeper dermal layers before they fully enter the bloodstream. This delayed absorption process means that the concentration of essential oils in the blood is relatively low after topical application.
• Systemic Circulation: Despite the lag in absorption, essential oils can still be absorbed into the blood via the skin, though at a significantly lower rate compared to oral ingestion.

Inhalation

Inhalation of essential oils leads to rapid absorption of molecules through the nasal mucosa and bronchioles, where they are directly absorbed into the bloodstream. This method allows for near-complete and rapid absorption, although the doses tend to be smaller compared to those administered through topical or oral routes.

• Study Example: A study on inhaling d-limonene, the major component in citrus oils, demonstrated that human volunteers absorbed up to 70% of the limonene over a 2-hour exposure. Only 1% of the limonene was exhaled unchanged, and 0.003% was excreted in the urine, with the majority metabolised by the liver and stored temporarily in adipose tissue.
• Elimination: The study suggested that after exposure to high doses, it could take up to 3 days for the limonene to be fully eliminated from the body.

Oral Intake

Oral ingestion of essential oils leads to much more rapid and complete absorption compared to topical application. When taken orally, essential oil compounds are absorbed through the mucosal lining of the digestive tract, particularly the stomach, and enter the bloodstream much more efficiently.

• Absorption: The oral route is typically more efficient, absorbing anywhere from two to ten times the dose compared to topical application.
• Metabolism: After ingestion, essential oils are processed by the liver, where they undergo metabolism. The metabolites formed in the liver can be responsible for the therapeutic effects, but they may also contribute to potential toxicity. Oral ingestion also has the disadvantage of potential gastrointestinal irritation, which can be alleviated with appropriate formulations like oil-filled capsules or emulsions.
• Toxicity Risk: Essential oils ingested orally pose a higher risk of toxicity, especially in large doses. This is due to the higher concentrations absorbed and their direct path to the liver for metabolism.

Rectal Suppositories

Rectal suppositories are an effective method for delivering essential oils and compounds directly into the bloodstream while bypassing the liver (the portal circulation). This method allows for the rapid absorption of essential oils into the systemic circulation, making it ideal for conditions that require a more direct route to the bloodstream. Rectal suppositories can be particularly useful for treating localised conditions in the lower colon.

• Absorption: The essential oils are absorbed directly into the general circulation, avoiding the liver's first-pass metabolism. This can result in more effective systemic distribution.
• Formulation Considerations: Just as with oral intake, it is crucial to respect the proper dose and dilution. Essential oils must be diluted appropriately (up to 10%) and mixed with suitable carriers to avoid irritation, as high concentrations of potent oils (like phenols) can be too irritating for this method.

Vaginal Pessaries

Vaginal pessaries are larger than rectal suppositories and are often used to treat infections or irritations in the vaginal area. Due to the high absorbency of mucous membranes, the vagina can quickly absorb essential oils, making this an effective route of administration for targeted conditions.

• Absorption: Like other mucous membranes, the vaginal mucosa facilitates rapid absorption of essential oils, allowing for quick therapeutic effects.
• Formulation Considerations: Pessaries can be made with vegetable oils, cocoa butter, or coconut oil, which help to slow absorption and reduce potential irritation. The concentration of essential oils in vaginal pessaries is typically higher (5% to 10%) compared to other routes, as the oils are diluted with non-irritating carriers. Tampons soaked in vegetable oil and essential oil mixtures are also commonly used.
• Water-Based Douches: These have a higher potential for irritation, so only low concentrations of essential oils (typically 0.25% to 1%) should be used to avoid adverse effects.

Lozenges

Essential oils can be added to chewable Vitamin C tablets or similar lozenges to help treat sore throats or infections. This method of administration allows for localised and gradual absorption of essential oils in the throat area.

• Absorption: Essential oils are absorbed through the mucosal lining of the mouth and throat, offering soothing effects for throat irritations or infections.
• Formulation Considerations: When using Vitamin C tablets or similar lozenges, it’s essential to carefully monitor the total amount of essential oils consumed. For example, if 1/2 to 1 drop of essential oil is applied to each lozenge, and 10 lozenges are consumed throughout the day, the total dosage may range from 5 to 10 drops of essential oil. While this is a moderate amount, it’s still important to ensure that the oils used are appropriate for this method and dosage.

To Conclude

Using essential oils can be incredibly beneficial when done correctly, but it’s all about finding the right dosage and application method. Whether you’re massaging them into your skin, inhaling their soothing scents, or even adding them to lozenges for a sore throat, the key is to understand how much to use and how your body absorbs them. Remember, everyone’s skin and body react differently, so it’s always best to start small, observe how you feel, and adjust accordingly. With the right knowledge and care, essential oils can be a wonderful addition to your wellness routine!