The Sweetheart



Sweet, low-cut and comfy this skimpy bikini has a thin lace trim and is a little cheeky in the bottom. Your period just got way cuter.

Flow: Light = 10ml / 2 regular tampons or Medium = 15ml / 3 regular tampons. 

Light: In the days leading up to your cycle, or the days leading out. 

Medium: useful for your entire period if you tend to flow light, or suitable from day 3 onwards if you flow on the heavier side.


Try risk free for 60 days*

As a first-time customer, you can try one pair of undies for 60 days risk-free. If you don’t like how they function, we will happily give you your money back (minus the cost of shipping).

Unfortunately, garments that have been worn can no longer be returned due to sanitary reasons. And you know, the market for second-hand underwear isn't all that flash!

So, we will require a brief explanation of the reason for your request.  The trial applies to one worn garment only.

No further refunds, credits or exchanges can be given on any additional worn or washed underpants.

Out of stock items

Current waiting time for out of stock items: less than 2 weeks (14/11/23).

Shipment of your in-stock items may be delayed until your pre-order item is ready for shipping. To ensure faster delivery of your in-stock items, we recommend making two separate orders - one for your pre-order items and one for your in-stock items.


Formulated with organic cotton and nylon made from recovered ocean plastics, these underpants whisk moisture away from your body (and plastics away from the turtles!), keeping you dry and "good karma'd" all period long.


Find our size guide here

*Disclaimer: The Sleep Tight run a little smaller than our other sizes, if you are in between sizes we would recommend choosing the larger option. Should you have any questions, please email us on and our team will be happy to assist further. 

Shipping & Returns

Flat rate shipping on all AU orders $7.95

International shipping to New Zealand $15.00

United Kingdom and USA $25.00

All in stock items are dispatched within 1-3 business days (excluding weekends, public holidays and busy sale periods) and deliver in 3-8 business days. 

Our undies are delivered to you by Sendle – Australia’s first 100% carbon neutral delivery service.

You may return all other unworn garments in original unopened packaging for a credit or refund within 30 days of your purchase. View our full return policy here

Customer Reviews

Based on 17 reviews

Works as described and feels amazing


Works as described…feels soft

Charlotte Venet
Love it!

Feels very confortable. Exactly what I was looking for.

So soft and silky

I love these. So soft and silky. They sit really well. They don't ride up or dig in anywhere, so no bulges or lumpy underwear lines from tight waistbands. They actually manage to feel cute and sexy, but still be very comfortable and absorb well. So pleased and will definitely be getting some more. Love. Thank you.

Shelly Coppock
Absolutely LOVE all the clever names of Wunderthings!

As this item is a gift for someone I have not tried them myself (over 55 and don't require them anymore), but I can only say that Wunderthings staff are so wonderful. My package got lost and right away staff sent out a new package and also sent me tracking information. All my emails were responded to very promptly and I really felt that they cared about me as a person and that is something hard to find in todays online ordering world, especially if something goes wrong. Thank you Wunderthings!