{"id":11570,"date":"2025-11-01T12:00:22","date_gmt":"2025-11-01T12:00:22","guid":{"rendered":"http:\/\/i-base.info\/guides\/?page_id=11570"},"modified":"2025-11-07T12:34:21","modified_gmt":"2025-11-07T12:34:21","slug":"on-demand","status":"publish","type":"page","link":"https:\/\/i-base.info\/guides\/prep\/on-demand","title":{"rendered":"Event-based oral dosing (2:1:1 or 2:7)"},"content":{"rendered":"

\"\"<\/p>\n

Event-based dosing involves only using PrEP when you want to have sex. It is also sometimes called on-demand dosing.<\/b><\/p>\n

Start with a double dose (two pills) at least two hours before you are going to have sex.<\/p>\n

However, instead of continuing to take daily PrEP, you only continue for either two or seven days \u2013 depending on the type of sex you have.\u00a0<\/span><\/p>\n

If you continue having sex for several days, just keep taking a daily pill. Then continue daily PrEP after the day you last have sex for either 2 or 7 days.<\/p>\n

Event-based dosing<\/b> is just as effective as daily PrEP. It is often used by people who have sex less often than once a week and who usually know when they might be likely to have sex.\u00a0<\/span><\/p>\n

Event-based dosing needs fewer pills, but it can\u2019t be used if you have hepatitis B.<\/p>\n

2:1:1 dosing<\/h2>\n

2:1:1 dosing <\/b>involves starting with a double dose and then taking daily PrEP for two<\/b> days after sex. Each dose should be roughly 24 hours after the previous one.<\/p>\n

2:1:1 dosing can be used by anyone for anal sex (if you are the insertive or receptive partner) or insertive vaginal\/frontal sex. It can not be used for receptive vaginal\/frontal sex.<\/p>\n

2:7 dosing<\/h2>\n

2:7 dosing<\/b> involves starting with a double dose and then taking daily PrEP for seven<\/b> days after sex. Each dose should be roughly 24 hours after the previous one.<\/p>\n

2:7 dosing needs to be used by cis women and trans and non-binary people who are having receptive vaginal\/frontal sex.\u00a0<\/span><\/p>\n

The pre-dose is important for the highest protection when using event-based dosing\u00ad\u00ad\u00ad\u00ad. But if you miss or are late with the pre-dose, start with a double dose as soon as you can.<\/p>\n","protected":false},"excerpt":{"rendered":"

Event-based dosing involves only using PrEP when you want to have sex. It is also sometimes called on-demand dosing. Start with a double dose (two pills) at least two hours before you are going to have sex. However, instead of …<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":11507,"menu_order":18,"comment_status":"closed","ping_status":"closed","template":"page-guides.php","meta":{"footnotes":""},"class_list":["post-11570","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/pages\/11570","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/comments?post=11570"}],"version-history":[{"count":6,"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/pages\/11570\/revisions"}],"predecessor-version":[{"id":19101,"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/pages\/11570\/revisions\/19101"}],"up":[{"embeddable":true,"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/pages\/11507"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/guides\/wp-json\/wp\/v2\/media?parent=11570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}