What is sublingual administration & how to do it correctly

Published On: 4 February 2022By

In this article we will cover what sublingual administration is and how to do it correctly. If you are using our GcMAFplus® spray, we particularly recommend reading this to ensure you receive the most benefits.

What is sublingual administration?

Sublingual is derived from the Latin word for ‘under the tongue‘. It is a common delivery method for many types of medications. By administering suitable substances under the tongue, these can be absorbed into the blood for systemic circulation.


Under the tongue are numerous mucous membranes comprised of connective tissue and capillaries. These are housed within a thin outer epithelium which suitable liquids and soluble substances can easily penetrate. This allows direct diffusion into capillaries for venous circulation. The blood supply to this region is provided by the sublingual and submental arteries. These branch off into the main external carotid artery and into the broader bloodstream. This means sublingual medicines can reach regions throughout the entire body via its extensive network of blood vessels, veins and arteries.

What substances can be administered sublingual?

Any type of substance can be administered sublingually so long as it can dissolve in saliva. This includes various types liquids, aerosols and powders. The PH, lipidity and molecular weight of a substance will determine whether it is suitable for this. Sublingual medicines come in a variety of formats including sprays (such as our GcMAFplus® spray), drops, strips, lozenges and tablets.

Advantages of sublingual administration

Sublingual administration is a very effective and quick way to administer medicines directly into the bloodstream. Compared to oral administration, it decreases the risk of degradation and enhances bioavailability. When taken orally, medicines must first-pass through the liver after being metabolised before they enter the blood. Sublingual bypasses this and the potential degradation which occurs in the digestive process by stomach acids and bile. It is a particularly effective delivery method for those who have trouble swallowing medications. Furthermore, when compared to injecting intravenously, sublingual delivery is a much easier and safer option to do yourself at home.


Generally it takes between 1-5 minutes for sublingual medicines to be absorbed into the bloodstream and start acting. For this reason it is often used for emergency situations requiring a fast response such as pain relief, blood pressure control and heart attacks. The thin epithelium overlying mucous membranes under the tongue allows suitable medicines to very quickly pass through. Some people use certain enhancer substances such as DMSO to assist the sublingual absorption process, however this is usually not necessary.

How to best administer medicines sublingual

The goal for this process is to absorb the substance into the tissue under the tongue and not swallowed. To best achieve this:

  1. Do not eat or drink for at least 15 minutes (or smoke for at least an hour)
  2. Wash your hands (or wear gloves) to prevent contamination
  3. Sit in an upright position and clear the mouth of any saliva
  4. Spray, drop or place the medication under the back of the tongue
  5. Hold it there for at least 30 seconds (or as per instructions)
  6. Wait at least another 15 minutes before eating, drinking or rinsing the mouth

Sublingual vs. buccal

Whereas sublingual absorption happens under the tongue, buccal is when substances are absorbed through the gum and cheek tissue. There are numerous tiny blood vessels in these regions which allow absorption into the blood. Like under the tongue, the buccal cavity is also lined with mucous membranes. These allow diffusion into the blood supplied to salivary glands and ducts via the jugular vein.

Both methods rapidly deliver medications, but depending on your condition and type of medication, there is a time and place for both. Buccal medications are often in the form of a soluble tablet which is placed between the gum and cheeks. Please consult instructions for the medication you are taking as to what is the best option.

Cautions and things to be aware of

Sublingual medicines should not be swallowed as this will reduce their effectiveness. Always sit in an upright position when administering to help ensure this does not happen. If you have an open sore or wound in the mouth, certain substances may irritate this. Please check the instructions for the medicine you are taking, or consult a doctor if this is the case. In rare circumstances general inflammation of the mucous membranes may occur from sublingual administration, even without any prior issues. Once again if this occurs please consult a physician. Essentially if you have any type of discomfort, pain, redness, swelling or bleeding in the mouth or tongue, either before or after taking sublingual medicines, you may wish to get this checked before continuing your treatment.


Sublingual administration is a very rapid, effective and safe way of administering medicines. This is why we chose it as an option for our GcMAFplus® products. Our sublingual sprays contain GcMAFplus® suspended in a neutral saline solution. This is readily absorbed into the mucous membranes under the tongue for venous circulation throughout the entire body. For this reason our spray option can be used to treat all manner of topical and non-topical conditions. Please use this as instructed for best effect.