Last updated: October 9, 2026

These terms are an agreement between you and Mast Cell Decoded (“we”, “us”) for using mastcell.net and its tools. By using the site, you agree to them. If you don’t agree, please don’t use the site.

Not medical advice

Mast Cell Decoded is for information only. It is not medical advice, diagnosis, or treatment, and it doesn’t replace your doctor. Always talk to a qualified healthcare provider about your symptoms, medications, and care. Never ignore medical advice or delay getting it because of something you read here. If you think you’re having a medical emergency, call 911 or your local emergency number right away.

What the forecast is

The forecast describes environmental patterns, such as air quality, pollen, pressure changes, cloud cover, and geomagnetic activity, that some people with MCAS watch. It is not a prediction of how you will feel. Triggers differ from person to person, and the science is still developing.

Forecasts are estimates built from third-party data. They can be wrong, late, or unavailable, and the way we calculate scores may change as we learn more. Please don’t make health or safety decisions based on the forecast alone.

Who can use it

You must be at least 18 years old to create an account.

Your account

  • Give us an accurate email address, and keep your password private.
  • You’re responsible for what happens under your account. We recommend turning on two-factor authentication.
  • Tell us right away if you think someone else has used your account.

Your information and content

What you enter stays yours. You give us permission to store and process it only to provide the service to you, as described in our Privacy Policy.

Using the site fairly

Please don’t:

  • Break the law using the site.
  • Try to get into accounts or systems that aren’t yours, or interfere with how the site works.
  • Scrape, copy, or resell the forecast or other content in bulk, or use automated tools to overload the site.
  • Use the site to harass or harm anyone.

Paid features

Today’s forecast is free. Some features, such as the full 5-day forecast and forecast emails, are part of a paid subscription. Before you pay for anything, we’ll show you the price and any terms that apply.

Subscriptions

  • Who you pay. Subscriptions are sold through Link, a service of our payment provider Stripe, which acts as the seller of record for your payment. Link processes the payment, sends your receipts, collects any sales tax or VAT, and handles payment questions, under its own terms shown at checkout. We never see or store your full card number.
  • Renewal. A subscription renews automatically at the end of each billing period, at the price shown when you subscribed, until you cancel. Your account page shows when it next renews.
  • Cancelling. You can cancel at any time from your account page (“Manage subscription”) or from your Link account. Your subscription stays active through the end of the period you’ve already paid for, then ends. You won’t be charged again.
  • Refunds. We don’t offer refunds for partial billing periods, except where the law requires otherwise. Link may also issue refunds in some cases under its terms. If something has gone wrong with a charge, contact us or Link support and it’ll be made right.
  • Price changes. If the price changes, we’ll email you before your next renewal, and the new price applies only from that renewal on. You can cancel before then if you don’t want to continue.
  • Failed payments. If a renewal payment fails, paid features may stop until it’s sorted out.
  • Deleting your account cancels your subscription, and you won’t be charged again.

Data from others

The forecast is built from weather, air quality, pollen, and geomagnetic data supplied by third-party providers. Their data is provided “as is”, and we don’t control it. Links to other websites are for convenience; we’re not responsible for their content.

Our content

The site’s design, text, graphics, and forecast scoring belong to Mast Cell Decoded. You may use the site for your own personal, non-commercial purposes.

No guarantees

The site is provided “as is” and “as available”. To the fullest extent the law allows, we make no promises that it will be accurate, complete, uninterrupted, or error-free.

Limits on our responsibility

To the fullest extent the law allows, Mast Cell Decoded won’t be liable for any indirect, incidental, or consequential damages, or for any decision you make based on the site. Our total liability for any claim is limited to the amount you paid us in the 12 months before the claim, or $50 if you haven’t paid us anything. Some places don’t allow these limits, so they may not all apply to you.

Ending your use

You can stop using the site and delete your account at any time. We may suspend or close accounts that break these terms or put others at risk.

Changes to these terms

If we change these terms, we’ll update the date at the top. If a change is significant, we’ll let account holders know by email before it takes effect. Continuing to use the site after that means you accept the new terms.

Contact us

Questions about these terms: [email protected]