Clinical review
Reviewer: Dr Arna Letica, GP, FRNZCGP, Auckland
Date of review: April 2021
Comments: The Natural Cycles app allows users to use basal body temperature measurements to identify fertile days of their cycle. This information can then be used as birth control (contraceptive) to prevent pregnancy or for planning conception. The app is most useful for females who want a hormone-free contraceptive option, or females who are wanting to optimise their chances of conception. Users would need to be motivated to record their temperature most days, and be prepared to follow advice (ie, using protection or abstaining from sex on fertile days). This app is a good option for females wanting to reliably track their fertility. However it is rather costly for a fairly basic tracking app, with minimal additional health information.
Safety concerns: The app is reported to be 93% effective with typical use, and 98% effective with perfect use – based on a large peer-reviewed study. It has been cleared by the FDA and meets required Health Standards products sold within the European Economic Area. It does, however, rely on users regularly entering data and following the instructions strictly. The app also specifies that its use does not protect against sexually transmitted infections.
New Zealand relevance: Yes, can be used by New Zealand users.
