Q and A


What are the pills marked with M171 and D100?


If your doctor prescribed HIV medication that looks like the pill in the picture and has M171 embossed, this is likely to be Tribuss.


Picture: Tribuss, manufactured by Aspen.

The picture is not very clear, but M171 is one one side and D100 is on the other.

This is based on the information at this website.


Tribuss is a generic version of Atripla and it is manufactured by Aspen. It is widely used in South Africa.

Just like Atripla, Tribuss contains three active HIV drugs – efavirenz, tenofovir-DF and emtricitabine.

Sometimes Tribuss is mainly used as an HIV treatment by people who are HIV positive. However, this is an older treatment that is steadily being switched to newer drugs in many countries.

Some countries use Tribuss as a way to prevent HIV after recent risk for people who are HIV negative. This way of using HIV meds is called PEP. Tribuss is not recommended as PEP in most countries though because of the risk of side effects that are higher in people who are HIV negative.

This answer was updated in December 2019 from an orginal question posted in September 2016.


  1. Roy Trevelion

    Hi Khaya,

    Please see this link for common side effects to Atroiza.

    However, fat loss has been linked to efavirenz which is the main drug in Atroiza. But this is a possible link only.

    Please speak to your doctor about your fat loss. You can ask to switch to other HIV meds. And you can check there are not other reasons for your weight loss.

    Please see this guide to fat loss (lipoatrophy) caused by early HIV meds.

  2. Khaya

    I’ve been on treatment since i know abt my status last month (Atroiza) and my CD4 count ws above 500…I noticed that I’m getting thinner and few weeks back one of my friend told tht my face is getting thinner

    Is there anything to worry abt because I hve a lot of appetite in food wise… Or is one the side effects

  3. Roy Trevelion

    Hi Themba,

    The answer above gives details of the pills marked M171. It includes links for more info too.

  4. Themba

    I saw the pills M171 in the beg of my girlfriend what is stead for?

  5. Roy Trevelion

    Hi Bukie,

    The answer above gives details of the pills marked M171. It includes links for more info too.

    But are you HIV positive. What questions are you asking exactly?

  6. Bukie

    I want to know about m171 it positive person

  7. Lisa Thorley

    Hi Ruty,

    There’s no need to take PrEP when someone is on effective treatment, this is because there isn’t any risk. Please see here: http://i-base.info/u-equals-u/


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