
LDN is a specialty medication meaning it’s custom-prepared by compounding pharmacies or “specials pharmacies” using the approved drug - naltrexone - but in a specially formulated way. Unlike medications in which ingredients and production processes are standardized, the formulation and quality of LDN will depend on the pharmacy that produces it.
LDNscience has compiled helpful guidance that explains the difference between LDN formulations and what you should look out for. Knowledge is power, and will enable you to make good LDN decisions.

The Different LDN Formulations
Capsules
Avoid lactose for people with lactose sensitivity
Tablets
Sometimes are scored so can be divided into smaller doses
Avoid lactose for people with lactose sensitivity
Liquid / Drops
Can be mixed into liquids. Allows very small dose modifications
Can have a bitter taste if placed directly in mouth
Important Other types of naltrexone formulations are available for other purposes. While these can have medical benefits, these formulations should not be confused with the regular well-studied “low dose” naltrexone (LDN).
- Slow-release or Extended-release: Such formulations should be avoided because they prevent the necessary rebound effect that makes low dose naltrexone effective.
- Cream: Since creams are absorbed slowly through the skin, they don’t provide the typical “rebound effect” necessary for low dose naltrexone to work.
Know about Fillers
A filler is an inactive ingredient that is mixed with naltrexone in order to ensure uniform filling and dosing. Certain fillers may physically bind with the LDN which prevents its necessary rapid absorption. Here is what you should know:
- Cellulose or plant-fiber fillers are more likely to bind with the LDN and slow its absorption. They are best avoided.
- Protein-based fillers (amino acids such as glycine) do not slow down LDN absorption.
- Simple-sugar fillers such as sucrose, dextrose, or lactose do not slow down LDN absorption.
- Lactose should be avoided by individuals with lactose intolerance, gastrointestinal issues, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD, such as Crohn’s and Colitis), and leaky gut syndrome.
- Propylene glycol (also known as methylethylene glycol), and glycerine are suitable for use in liquid LDN formulations.
Choose the Best Pharmacy For You
To find the right compounding pharmacy to prepare your LDN, a great start is to look at LDNscience’s free global compounding pharmacy directory. It is an excellent resource to find a pharmacy closest to you that is familiar with LDN preparation. You can discuss with them (in addition to your LDN prescriber) what formulation and fillers would be best for you. By following these steps, you can ensure that your LDN experience is as optimal as can be.