To (1) explore and analyse current online preconception health and nutrition-related claims, (2) assess identified online preconception health claims against current preconception guidelines and (3) understand the perceived health claims among reproductive-aged men and women.

Five online media platforms were searched using fertility nutrition-related search terms.

All claims were assessed by an expert panel against nine Australian and International preconception guidelines. A sample of eighty reproductive-aged men and women rated a random sample of claims.

A content analysis of 191 claims was conducted using NVivo 12 Plus to group recurring topics into themes and then categories. Survey participants rated forty claims using a 5-point Likert scale from ‘Not at all likely’ to ‘Highly likely’. If at least 75 % of the surveyed population considered a claim ‘likely’ or ‘unlikely’, it was classified as such.

Two themes were generated: nutrition claims and lifestyle claims. Five percent of claims were present in preconception guidelines, while 54 % had no evidence to support the claim. The highest percentage of no evidence claims was for whole foods and their components and dietary patterns. TikTok and Instagram contained the highest proportion of non-evidence-based claims. The community considered 3/40 claims likely to be true and 3/40 claims unlikely to be true.

There is a myriad of inaccurate information online related to fertility nutrition and lifestyle behaviours. Social media public health campaigns to disseminate quality evidence for preconception health are necessary to improve awareness among those who access online information.