FaSSIF/FeSSIF/FaSSGF: Product Benefits

Biorelevant Media simulate gut fluids before (fasted) and after (fed) eating food. They are really useful for predicting what will happen to your product when it enters the gastro-intestinal tract. In the past the media were notoriously difficult to prepare.

In 2007 we solved this problem by inventing a product that makes Biorelevant Media instantly. Originally known as ‘SIF Powder’, now as ‘FaSSIF/FeSSIF/FaSSGF’, it offers so many benefits:


You can make 3 different media (FaSSIF, FeSSIF or FaSSGF) from 1 powder.

Quick and easy to use

Simply add powder to buffer and you're ready to go...

Reproducible results

We use the highest grade of ingredients and double check their purity before manufacture. The powders are made in our own facility in London so we can control every aspect of their production. Once this process is complete, they are only released after rigorous analysis by an independent laboratory in Germany. These steps ensure you will get highly reproducible results from our products every time you use them.

Great value

3 bottle sizes are available so whether you want to make 10 mL or 1000 L of Biorelevant Media, we can satisfy your requirements. The powder has a long shelf life of 18 months so there is no need for any waste. We also offer money-saving 4 packs.

Tried and tested

Our FaSSIF/FeSSIF/FaSSGF product has thousands of loyal customers from small start ups to the biggest companies in the Pharmaceutical industry. It's referenced in hundreds of publications and is the perfect introduction to Biorelevant Media.

“We use the powder for preparation of different biorelevant media (FaSSGF, FaSSIF and FeSSIF) for solubility and dissolution studies. The method of preparation of the media is very easy to follow and we get biorelevant media of high quality. The short time needed for their preparation and the reproducibility of the media are great advantages of this product. The support from the biorelevant.com team is excellent!”

Dr Nikoletta Fotaki, Senior Lecturer in Pharmaceutics, University of Bath