CORE:TX™ 3.0
Our thinnest gusset designed to provide comfortable support for your daily needs. Wear it as your regular underwear, enhanced with a built-in absorbent leakproof liner. Most suitable for lighter days.

CORE:TX™ 5.0
Composed of multiple thin and lightweight absorbent layers. It provides medium absorption and all-day comfort with protection for moderate flows.

CORE:TX™ 9.0
The best teammate when you're working up a sweat. Created with multi-layer high-absorption fibres to match your peak performance while offering uncompromised comfort and protection, no matter what activity you're doing.

The CORE:TX™ 3.0 underwear gusset works in two layers. The 3.0 gusset has a moisture-wicking layer to keep you dry and a waterproof layer to prevent leakage. We recommend CORE:TX™ 3.0 for your lighter days or everyday wear.

The CORE:TX™ 5.0 and 9.0 underwear gussets work in three layers. The gussets have a moisture-wicking layer to keep you dry, a water-absorbent layer to hold fluids securely, and a waterproof layer to prevent leakage. We recommend CORE:TX™ 5.0 for medium flows and CORE:TX™ 9.0 for heavier flows.

CORE:TX™ 3.0 - Up to 1 tampon or pad

CORE:TX™ 5.0 - Up to 3-5 tampons or pads

CORE:TX™ 9.0 - Up to 5-7 tampons or pads

Each flow is different. When you are trying out our CORE:TX™ underwear for the first time, we recommend checking your underwear throughout the day to understand the CORE:TX™ absorbency level and your flow. On heavier days, we recommend changing your underwear at least twice a day, once during the day and once at night.

It feels like wearing your regular underwear. Our CORE:TX™ gussets were designed for maximum comfort while keeping you protected throughout the day and night.

Our CORE:TX™ underwear was designed to be worn without needing any additional protection, as long as you find the perfect absorbency level that matches your flow throughout your cycle.

For those who prefer menstrual pads for your added protection, our CORE:TX™ 5.0 and 9.0 underwear feature a partially detached gusset to accommodate the wings of menstrual pads so they securely and discreetly stay in place.

We recommend rinsing your underwear after each use until the water runs clear. Place it in a wash bag and machine wash cold, or alternatively, hand wash if you prefer.

Do not tumble dry, bleach, or iron.

All CORE:TX™ underwear and activewear should be hang dry to preserve its quality.

Our CORE:TX™ 3.0 leggings and shorts have a built-in 3.0 gusset for reliable protection during your workout or training sessions on lighter days. They can be worn on their own, or with additional protection of your choice.

Our size guide is a general guideline for helping you find your ARES size. You can check it out here.

Gift cards are delivered by email and contain checkout redemption instructions. Our gift cards have no additional processing fees.

Discount codes cannot be applied to purchase gift cards. There are no refunds on gift card purchases.

Usage Restrictions — Gift cards are non-transferable and non-refundable and cannot be redeemed for cash unless required by law. Gift cards are valid only at athelticus.com and cannot be used at unauthorized locations. Certain products, promotions, or services may be excluded from gift card use.

Balance & Expiry — Gift cards do not expire unless otherwise stated. Any unused balance will remain on the card for future use. Cardholders can check the remaining balance online.

Currency and Usage — Gift cards are available in Canadian Dollars (CAD) or US Dollars (USD). The currency of the card must match the currency of the store or website where it is redeemed. Gift cards cannot be exchanged for cash in any currency unless required by law. Prices and transactions will be processed in the currency of the gift card. Currency conversion is not supported.

Confirmation — You will receive a confirmation email after your purchase, as well as a notification once the Gift Card has been shipped or sent to the recipient.

Tax — Digital Gift Card purchases are not subject to sales tax. However, applicable taxes will be applied to items purchased using a digital Gift Card.

Experience CORE:TX™ Leakproof Underwear with confidence—enjoy a 45-day money-back guarantee.

Learn more about it here.

When your order is prepared for shipment, we will send you an email containing a shipping confirmation that includes your order number and tracking details. You can also track your order by downloading the Shop App.

You can monitor your order's progress by visiting the Order Status page sent in your shipping confirmation email. If you require further assistance with your order, please contact our Support Team at hello@athleticus.com and we will do our best to assist you with your order.

Please provide your order and tracking ID, full name, email address, shipping address, and the missing item(s) from your order.

We’re sorry to hear that you received a defective item(s). We’re here to help! Please contact our Support Team at hello@athleticus.com and we will do our best to assist you with your order.

Unfortunately, we are unable to make any modifications or changes to your order after the checkout process is finalized. Please contact our Support Team at hello@athleticus.com and we will do our best to assist you with your order.

We accept Visa, Mastercard, Amex, and Discover cards on our site. Credit card gift cards are also valid and can be entered as regular credit cards! We also offer Klarna, Apple Pay, Google Pay, PayPal and ShopPay as express checkout options.

Please read more about Klarna here.

We currently ship to the contiguous United States and Canada.

We are not able to ship to US territories (American Samoa, Guam, Northern Mariana Islands, Puerto Rico, and U.S. Virgin Islands) at this time.

Canada Orders

Orders over $50* CAD: Free Standard Shipping

Orders under $50* CAD: Calculated at checkout.

Orders to Yukon, Northwest Territories, and Nunavut are subject to a $25 CAD delivery fee.

US Orders

Orders over $50* USD: Free Standard Shipping

Orders under $50* USD: Calculated at checkout.

We currently do not ship to Alaska and Hawaii.

*Excluding taxes, discounts, and shipping.

You may be subject to state or provincial taxes and any additional duties as per your local regulations. These taxes will be calculated during the checkout process.

Please allow 1-2 business days for our warehouse team to prepare and ship your order. During peak periods, please allow up to 4 business days for order processing. Once an order is submitted, we cannot guarantee any modifications to the address, orders, or cancellations. Orders placed after 1 PM on Fridays will be shipped on the subsequent Monday.

Standard shipping:
3-9 business days

Express shipping:
2-3 business days

Unfortunately, we do not ship to P.O. Boxes at the moment. If you require assistance with placing your order, please reach out to our team at hello@athleticus.com and we will do our best to assist you.

Returns and exchanges are eligible within 30 days from delivery date, except for final sale items.

Each pair of our CORE:TX™ Underwear is individually sealed to ensure the highest standards of hygiene. For health and safety reasons, we are unable to accept returns or exchanges on any underwear that has been opened from its original packaging.

CORE:TX™ UNDERWEAR

Individual CORE:TX™ Leakproof Underwear

To be eligible for a return or exchange, the underwear item must be unopened in its original condition with all packaging intact. It should not show any signs of use, including opened package, stains, odors, or damage.

CORE:TX™ Leakproof Bundles

To be eligible for a return or exchange, ALL 3 underwear must be unopened in its original condition with all packaging intact. If one pair has been opened, we are unable to process an exchange for the bundle.

CORE:TX™ Leakproof Kits

Our Leakproof Kits are final sale and not eligible for returns or exchanges due to hygiene and packaging restrictions.

If you are unsure about the size, style, or absorbency that's right for you, we highly recommend trying a single pair first through our 45-Day Risk-Free Trial before purchasing a Bundle or Kit. This way, you can find your perfect fit with confidence.

CORE:TX™ ACTIVEWEAR

To be eligible for a return or exchange, items must have their tags intact, be unworn, unwashed and in its original condition. They should not show signs of use, including stains, odors or damage. We reserve the right to returns or exchanges if the clothing item is not in the required condition.


ESSENTIALS

Essential Underwear & Bundle

To be eligible for a return or exchange, the underwear must be unopened in its original condition with all packaging intact. It should not show any signs of use, including opened package, stains, odors, or damage.

Socks

For hygiene reasons, all sock purchases are final sale and are not eligible for returns or exchanges.

You can get started with a return or exchange for all eligible items or return a gift for store credit through our Return Center or by contacting us at hello@athleticus.com.

We do not accept returns or exchanges on final sale or clearance items.

We gladly accept the return of gifted items bought online in exchange for store credit. To be eligible, the item should be in its original condition, with tags intact, and must not have been worn, washed, or used. You may initiate your return in our Return Center or by sending us an email at hello@athleticus.com with your Order Number and Zip/Postal Code.

By purchasing from Athleticus Research, you agree to the following return policy terms:

1. Final Sale Items – Certain products, including Leakproof Kits and Socks, are final sale and not eligible for returns or exchanges due to hygiene and packaging restrictions.
   
2. Exchanges – Exchanges are subject to product availability. If the requested item is unavailable, we will provide a refund or assist you in finding an alternative product.
   
3. Eligibility – To qualify for a return or exchange (where applicable), items must be unused, in original packaging, and meet our return criteria outlined under our Return and Exchange Policy.
   
4. Risk-Free Trial – First-time customers may qualify for our 45-Day Risk-Free Trial on select products. This offer is limited to one item per customer and does not apply to bundles or multi-packs.
   
5. Return Process – Approved returns must be initiated through our return portal or by contacting our support team at hello@athleticus.com. Return shipping costs are the responsibility of the customer unless otherwise stated.
   
6. Damaged or Defective Items – If you receive a defective or incorrect product, please contact us within 30 days of delivery for a resolution.
   
7. Refunds & Processing – Refunds (if applicable) will be issued to the original payment method within 7 business days after the return is processed. Shipping fees are non-refundable.
   
8. Right to Refuse Returns – We reserve the right to refuse returns or exchanges if the underwear item is not in the required condition (in its original packaging, unworn, and unwashed).
   

For any questions regarding our return policy, please reach out to hello@athleticus.com