Can I Take PrEP 3 Hours Late? Get The Answers

We live in the real world, and there will be days when we take our pills late or *gasp* even miss a pill. We’ve poured over studies to find out if you can take PrEP two hours late, three hours late, and even a week late.

Before you read this article, we want to remind you that any medical decisions and questions about PrEP—or any other medication you’re on—should always be discussed with your healthcare practitioner.

This article uses scholarly sources to give you the most up-to-date information on PrEP, but taking all prescriptions as directed by your healthcare provider is integral.  So, if you’ve been wondering things like, “what do I do about a missed PrEP dose?”, “can I take PrEP 3 hours later than usual?”, or “what does ‘PrEP 2 1 1’ mean?”, this page is for you.

What is PrEP & How Does it Work?

You likely already know about the two types of PrEP, but if not, here are some basics: 

• PrEP is a once-per-day pill that helps to reduce the risk of HIV. It can reduce the risk of contracting HIV by over 90%. 
• There are two types of PrEP, pre-exposure and post-exposure (referred to as PEP). PEP is more than 80% effective. 
• PrEP and PEP require following a regular dosage schedule to be as effective as possible.

If you have more questions about what PrEP is and its effectiveness, check out our PrEP FAQ.

How PrEP Works:

At its most basic, PrEP works by blocking an enzyme that the HIV virus needs in order to replicate itself. Because it can’t make copies of itself, the virus quickly dies off in your body, before it can infect you or spread.

This is part of the reason that maintaining a steady state of PrEP medications is so valuable for your body, because once you reach this point, your body can easily break down the HIV virus, no matter when or how you’re infected.

However, if you missed PrEP dosing then that steady state may become unstable, which can create opportunities for infection. That’s part of the reason why it’s so important to follow your practitioner’s instructions on how to take your PrEP treatments effectively, depending on the type of treatment you’re using.

PrEP Dosing Schedule Breakdown:

There are two kinds of PrEP treatment cycles: once-a-day pills and on-demand PrEP dosing.

Once-a-day pills work exactly how they sound. You take one pill each day (as close to the same time as possible), in order to reach/maintain a steady state of PrEP medication in your bloodstream.

On-demand PrEP dosing, also known as the PrEP 2-1-1 dosing schedule, involves taking 2 PrEP pills between 2-24 hours before having sex, followed by 1 pill 24 hours after the first 2 pills, and another single pill 24 hours after the 3rd.

While PrEP 2-1-1 dosing can be effective, it doesn’t offer as much well-rounded and continuous protection as once-a-day PrEP pills can provide.

Can Occasional Missed or Late Doses Affect PrEP’s Effectiveness?

Yes, but how much it's affected will depend on the type of PrEP treatment you’re using, and how long it’s been since your last PrEP dosing. This begs the question, how effective is PrEP if you miss a dose?

If you’re using once-a-day PrEP pills and you’re wondering “can I take PrEP 3 hours or so late?”, you absolutely can. However, your PrEP dosing effectiveness may be slightly impacted.

Because you’re taking the medication every day, taking PrEP dosages late can have a small impact on your protection levels, but as long as it doesn’t happen frequently or result in multiple fully missed doses of PrEP, you should still be largely protected from HIV.

On-demand PrEP, or 2-1-1 PrEP dosing, is a different story. Because you’re only taking 4 total PrEP pills to protect you from HIV, missing one of these pills could drastically alter your levels of protection. Even taking it late could alter your protection, so it’s vital if you’re using a 2-1-1 PrEP dosing schedule that you do your best to maintain consistent, accurate timing for PrEP dosages.

Can I Take PrEP 3 Hours Late?

Yes, you can take your PrEP pill a few hours late so that, so you will never again need to search for, “Can I take my prep 2 hours late” again.

The main goal of PrEP is to aim for taking it every day, but your body isn’t going to instantly make you susceptible to HIV if you take a pill late.skip a pill. The most important time to take your PrEP pills every day is during the first 30 days (about 4 and a half weeks).

This allows your body to build up the medication, so if you miss a dose here or there, you’re still protected (a process known as ‘steady state’).

What Happens if I Take My PrEP 3 Hours Late?

You should take your PrEP pill within 12 hours of missing your original dose to ensure you keep that 99% effective rate up or to get your body used to the pill if you’re newly taking them. So, if you’ve just missed your PrEP dose, you can definitely take it without concern 3 hours later than normal.

It’s not a good idea to let this happen too often, as it can begin to affect the state of PrEP medications in your body, which could reduce your potential protection against HIV.

If you find yourself more than 12 hours after your missed dose, skip taking the pill and get back on your normal routine the following day. Again, studies show that PrEP begins to lose its effectiveness after 24 hours, dropping down to 97%, so as soon as you remember to take the pill, you’ll want to get back on schedule.

What Happens if I Take PrEP Twice in One Day?

One of the most common scenarios people face on PrEP is missing a dose and then wondering if they need to take two pills when they finally remember. Or, they forget they took a dose and take another one a couple of hours later.

The good thing is that you’re not going to risk injuring yourself if you take a second dose of PrEP. The bad thing is that you’re much more likely to face side effects, including:

• Headache
• Nausea
• Diarrhea
• Rash

If you miss a dose, you’ll be fine. Don’t double up because the process won’t make the medication more effective; instead, it just makes you feel sick.  Again, if you have questions about this at all, always check in with your prescribing doctor.

Should I Take My PrEP in the Morning or at Night?

There’s no right time to take PrEP. The time you take your prescription depends entirely on your schedule. Your main goal is to take it at the same time each day.

For example, if you work nights and sleep in on your days off, you probably wouldn’t want to take it in the early morning hours. Instead, taking it in the early evening before you go to work and when you’re likely to be awake even when off will likely help you stick to a regular dosage schedule.

Is PrEP Effective for People with Vaginas?

Many rumours are floating around about the effectiveness of PrEP for people with vaginas. The World Health Organization relies upon a study completed in 2016 by Dr. Mackenzie Cottrell et al. showed vaginal tissue absorbs the medication more quickly.

However, the same study found that women who routinely miss doses can reduce their protection by as much as 33%, even when their rectal tissue is 95% protected. Just like those having anal sex, people with vaginas should be aiming to reach a “steady state,” which takes an estimated 21-30 days for most people to reach. 

As of 2014, an estimated 75,500 Canadians lived with HIV, and up to 20% were unaware they had it. By utilizing PrEP as part of a daily routine, rates of new HIV will decrease.

Although missed PrEP doses will not severely throw off your body’s immunity, especially once you’ve reached a steady state, you should aim to take a PrEP pill within 12 hours of missing your regular dosage time or make sure you take your next pill at your regular time. 

Do not double up on pills if you miss a dose, and remember to plan to take your pills at the same time each day to maintain your PrEP dosing effectiveness. Together, we can make HIV a thing of the past!

PrEP is an effective way of reducing the risk of HIV transmission. However, it is essential to remember that it does not offer complete protection against other sexually transmitted infections (STIs).

Therefore, it is still important to practice safe sexual behaviours, including using condoms, even when taking PrEP as part of your preventive healthcare routine.

Getting to a Steady State with PrEP

Any medication that functions best with a ‘steady state’ is just a fancy way of saying that you’re trying to keep a consistent amount of the medication in your system from day-to-day.

The best way to achieve and maintain a steady state with PrEP is to ensure that you’re taking your PrEP at the same time, each time you’re due for another dose.

If you’re trying to make up for a missed PrEP dose, there is a chance that it could impact the steady state of PrEP medications in your body. However, if you’re usually taking your PrEP doses on time, the impact should be minimal. It’s when this starts to become a regular trend that it can begin to drastically alter your levels of protection against HIV.

With on-demand PrEP dosing, there’s less of a concern about maintaining a steady state of protection, as these types of PrEP don’t have to be taken as regularly as other forms, in order to offer you protection.

Tips to Stay on Track with Your PrEP Dosing

Let’s talk about some tips that you can use to avoid having to wonder “can I take my PreP 3 hours late?”. Here’s a list of tips that you can use to help stay on track with your PrEP to avoid missed doses:

• Set alarms to help you remember dosages
• Take your dosage during a time of the day as another daily event (i.e., breakfast, noon, bedtime, etc.)
• Keep your PrEP medications somewhere easily accessible or that you’ll see throughout the day
• Take PrEP medications with you, if you’re unsure what time you’ll be home from an event
• Build your PrEP dosing into your daily schedule, including adding it into your calendar to trigger notifications and prevent missed PrEP doses

Get On-Demand Treatment for Your Everyday Health

Felix makes it quick and easy for people across Canada to access PrEP medications from the comfort of their own home. No more long waits at doctor’s offices or having to stand in line at the local pharmacy.

Not only can Felix provide PrEP prescriptions, if your practitioner believes it’s an appropriate treatment for you, but our pharmacy partners can ship your medications directly (and discreetly) to your door - at no extra cost!

To get started, just complete a short online assessment (at your convenience), and one of our clinicians will typically get back to your request within 24 hours.

This is just one of the ways that Felix is helping Canadians take back control of their sex lives and quality of life, so that you can get back to living life on your terms - the way it should be.