Understanding cancer myths and misinformation
Seen something about cancer online that's left you confused or worried? You're not alone, and we're here to help.
All of Macmillan’s cancer information is reviewed by medical experts and meets strict quality standards. We're PIF TICK certified which means our health information has been carefully checked and approved. This means we can give you clear, evidence-based information you can trust.
Why this matters
Every day, thousands of people find confusing or misleading information about cancer online – particularly on social media. Sometimes people share this information because they are trying to help.
Here is what we know:
- More than half of UK adults (58%) believe something about cancer that isn't true.
- Wrong information can increase worry and delay people seeing their doctor or getting treatment.
- Misleading claims often spread quickly on social media and it affects people of all ages.
Source: Over half a million young adults think cancer only really happens in old age
With more than 400,000 people diagnosed with cancer each year in the UK, clear and trusted information matters more than ever.
Our cancer statistics fact sheet gives you easy to understand facts which are backed by evidence.
Common cancer myths explained
You might have heard some of these ‘myths’ about cancer. Let's look at what's really true.
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Does sugar 'feed' cancer?
This is one of the most common worries people have. There is no evidence that shows sugar directly increases the risk of cancer or encourages it to grow.
Read more about diet myths and cancer risk.
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Does Ivermectin treat cancer?
On the Joe Rogan Experience podcast, film star Mel Gibson spoke of friends who took the anti-parasitic drugs ivermectin and fenbendazole. But so far Ivermectin has not been shown to be effective at treating cancer.
Read Professor Richard Simcock’s article Cancer and ivermectin: What people with cancer need to know.
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Can mistletoe treat cancer?
You might have seen this shared online or heard about it from others. Currently there is no reliable evidence to show that mistletoe will treat cancer. Using mistletoe as an alternative to cancer treatments is not advisable.
Not sure what the difference is between alternative therapies and complementary therapies is?
Alternative therapies are treatments used instead of conventional cancer treatments. They may claim to treat or even cure cancer. But there is no scientific proof to support these claims. Alternative therapies are also known as alternative medicine.
Complementary therapies are treatments that people may use with, or as well as, conventional medical treatments. Complementary therapies should not claim that they can treat or cure cancer.
Learn more about complementary therapies.
How to check cancer information
Finding trusted information can help you make informed choices. Before trusting health information online, ask questions:
- Is the source credible? Use sources such as the NHS, charities like Macmillan, or recognised health organisations.
- Is there evidence? Reliable content links to research or explains how it’s reviewed.
- Beware of miracle cures. If it sounds too good to be true, it probably is.
- Who wrote it and why? Influencers and forums are not always medically accurate
- Is it up to date? Check review dates.
- AI-generated? If it’s from an AI tool, ask what sources were used.
- Check for quality marks like the PIF TICK logo.
Learn more in our video, 6 tips on how to find reliable health information online.
How we can help you
You don’t have to deal with confusing information alone. We're here to help you find the facts and answer your questions.
We offer:
- Trusted information – everything we share is checked by cancer doctors and nurses.
- Real experiences – stories from people who've been through cancer.
- Expert support – our Support Line team can help you understand information.
If you're worried or need to talk:
- Call our Support Line free:0808 808 00 00, 8am to 8pm, 7 days a week.
- Email us or use online chat (click on the 'chat to us' button on our website).
- Talk to your GP. They can give you advice that's right for your situation.
Real stories
Did you know?
Last year, people affected by cancer got support from Macmillan in different ways. Some you might not know about.
Source: Macmillan annual report
Online Community
Support services
Macmillan Telephone Buddies
About our information
This information has been written, revised and edited by Macmillan's Cancer Information and Development team and our Digital Content Editor team. Learn more about how we produce our cancer information.
Accurate information helps you make informed choices. Rely on expert sources such as Macmillan Cancer Support, the NHS and your own healthcare team.
Date reviewed
Reviewed: December 2025 | Next review: December 2028