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. Lisa Thorley

    Hi Winn.

    Your viral load is still undetectable, this is because its 50. If it were to rise above 50 then this would be detectable.

    Though there can be pressures due to work, its really important that you eat and that you look after yourself. Are your meds supposed to be taken with food?

  2. Winn

    Hi, my viral load was undetectable and now it’s 50 copies. I have been taking efavirenz/lamivudine/tenofovir disoproxil fumarate for 6years now without missing. Although i changed jobs and for my current job sometimes i end up eating one meal a day because of the pressure to meet deadlines. Could it be the problem? How can I achieve undetectable Viral load again? What should I do in this case? I am worried.

  3. Lisa Thorley

    Hi Jazz,

    Its common that people can forget to take their meds. Taking it at 4am and then again at 11pm is perfectly fine.

  4. Jazz


    I am taking efavirenz/lamivudine/tenofovir disoproxil fumarate for about 1 year now.

    I am undectable since November 2017.

    I usually take the drug at around 11pm. However, yesterday I was so tired and slept off. Then, I suddenly woke up at around 4am and I drink the pill immediately, instead of missing a dose. Is this alright?

    Also, should I stick back on taking it at 11pm since I was late this day?

    Thank you

  5. Lisa Thorley

    Hi Tania,

    Its possible that this could be a side effect of the meds due to missing them for 3 days. However it could also be the alcohol. How long have you been on meds for? Have you ever missed meds for this length of time?

  6. Tania

    I have a terrible headache I am taking tribbus ARV..i skipped them for 3 days and dranked alcohol when I resumed taking my tablets again after 3 days I started having a terrible headache I dnt know what cud be the reason



  7. Lisa Thorley

    Hi Priscilla,

    Could you please confirm what your viral load is as they don’t come in 0.5000.

  8. Priscilla

    My previous results showed 0.5000 viral load and 715 CD4 count which was good. But since then my schedule has gone from bad to worse to a point where I have had to change my intake time twice already.

    I used to take them at 9:30 pm, then I took them at 10 am for about two days and the side effects started to affect me at work, now I take them at 4:00 pm.

    Should I be worried about my record changing from good to worse?


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