Q and A


Is it ok if I take my meds 15 or 30 mins late?

Do you have to take your arvs at exactly the same time each day? Will for example 30 mins (or even an hour) each way have any impact whatsoever on the suppression of the virus or cause resistance? I am worried as even though I take them every day some days it is 15 or 30 mins later or earlier than the previous day.


Thank you for your question.

It is sometimes difficult to take your meds at the exact same time everyday.

Even when starting, there is a window of about an hour either side of your target time when it is still fine to take them.

For example, if you want to take your meds every night at 10 pm, then any time between 9pm and 11pm will be fine.

Everyone has a few times when we forget our meds though.

The less this happens the better. But if it does happen once in a while then there is nothing to worry about. If you forget in the future, take them as soon as you remember. However, if this is already close to the next dose DO NOT take a double dose.

Once you get an undetectable viral load, especially if it has been undetectable for several years, you have more flexibility. This partly depends on which drugs you are using.

Some once daily drugs (including tenofovir DF, emtricitabine and efavirinz) have long half-lives. This means drug levels stay in your body for long enough to cover being several hours late or even missing a dose completely.

Several studies are looking at whether reduced dosing might be safe – for example by only taking ART for four days a week. We need bigger studies before we know if this is safe though.

Note: this question was updated in October 2016 from and original answer in April 2011.


  1. Simon Collins

    Hi Ananda

    Tribuss contains three HIV drugs (ARVs) – efavirenz, FTC and tenofovir DF.

    The efavirenz means this should be taken before you go to sleep in order to reduce side effects.

  2. Ananda

    Hi , I’m on Pep Tribuss , I take my meds everyday at 15:30. For the last 4 days the times have been different, but I have been taking it everyday. What is the best time to take it .

  3. Simon Collins

    Hi Rosina, thanks. Lots of HIV meds can be taken at a time that is best for you. But a few are better to take either at night or in the morning. If your combination includes efavirenz, this is better to take at night. If your combination includes dolutegravir, this is better to take in the morning. Following this advice should help you sleep better but please talk to your doctor who can go through this in more detail.

  4. Rosina

    My cd4 count its 250, am taking my meds at 21h00, can I change it to 05h45 before I go to work. Am struggling to sleep and am only gonna see my Doctor on the 30th. Please help

  5. Simon Collins

    Hi Elizabeth, please tell your doctor about this. There may be things that can help depending on which drugs you are using. Or you might be able to use a different combination.

  6. Elizabeth

    I took arv and I always got headache


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