How do I use the Undu 'Original' Heat Pack? 

1- First Time, Soften: When your Heat Pack arrives, it will be stiff. Run hot water over it OR let it sit in a dish of hot water until it has softened.

2 - Heat it: The Heat Pack can now be heated in a mug with boiling water, in the microwave, or on the stove!

*If you ever see oil in the water, consider the Heat Pack broken and do not continue to use it. Send us an email at:

3 - Wear it: Carefully remove the Heat Pack. Always have a layer of fabric between you and the Heat Pack. The ‘Keep It’ Brief is ideal! Place the Heat Pack on your lower abdomen or back to feel relief. Repeat for as many times as you’d like! 

4 -Storing: When you’re finished with the Heat Pack, roll it up while it’s still soft and place it in the cloth bag provided. This will remove Step 1 next time you use it! 

As always, take care when using hot water!

Check out this blog post from one of our Founders for more info!

How long does the heat last? 

The ‘Original’ Heat Pack currently provides heat for up to 50 minutes! Doctors typically recommend applying heat therapy in 20-30 minute intervals.

What size underwear am I? 

Our sizing is simple! We’ve decided to directly reflect your waist dimensions in the sizing of our underwear. If you have a 24”-25” waist, select size 24-25. More questions? See the chart below!


[Back to Briefs!]

What about returns? 

We want you to feel safe, comfortable, and relieved!
If that’s not the case, reach out to us at and we’ll figure it out!

Do you sell outside of Canada? 

Right now we are made entirely in Ontario and are proud to be launching exclusively in Canada!  We’re excited to grow and sell to more parts of the world. Join our mailing list to stay up-to-date on our progress!

What can I expect after I place an order? 

First of all, thank you for supporting our new business! We never thought our launch would occur during a pandemic…

In our efforts to be a sustainable company, we secured pre-orders before we went into production so we knew exactly how much of each product to make.
Based on those orders, we've built up our inventory to reflect the most popular purchases so far. 

When you place your order, you’ll get an email from us and we’ll make sure to keep you posted every step of the way! We estimate that all orders, including pre-orders, will be shipped out in May 2021. 

Feel free to send us an email with any questions!

Why heat?

Heat therapy has been used since 500 B.C. Applying heat to the outside of the body is a noninvasive way to treat muscle aches and pains… like menstrual cramps! The heat loosens tissues and stimulates blood flow to the area, promoting healing, decreasing pain, and relaxing muscles. 

We conducted a survey and learned that 61% of people who experience menstrual pain use heat to relieve their symptoms. Here’s a helpful article where you can learn more! 

It’s always a good idea to consult with your doctor if you have any concerns.