OmneDiem: US shipping, international orders, customs and 30-day returns
OmneDiem is a US brand of supplements built around the enzyme diamine oxidase (DAO), with further lines such as probiotics, omega oils and multivitamins. The shop is based in Michigan, so the shipping rules lean towards American customers. If you live elsewhere, the section on international orders is the one to read first.
Shipping inside the US
The shop ships Monday to Friday and closes on permanent federal holidays. An order placed by 11:00 am Eastern Time normally leaves the same day; later orders go out the next business day. Three speeds are listed: Standard via USPS takes 7 business days after the item ships, UPS Ground 3 to 5 business days, and UPS Next Day Air or 2nd Day Air are the fastest. Free shipping offers always use the USPS standard method and apply to US and US territory addresses only. UPS, FedEx and DHL do not deliver to PO boxes. If a parcel is delayed, the shop asks you to wait 30 days from shipment for US orders and 60 days for international ones before it can step in. For mail orders paid by check, processing the payment alone takes 3 to 7 business days.
Ordering from outside the US
The country selector in the shop footer includes Germany, Austria, Switzerland, the United Kingdom and Canada. Two international methods are named:
- USPS First-Class Package International, North America only, up to 20 business days after shipping.
- UPS Worldwide Expedited, 7 to 10 business days after shipping.
These times count only the carrier's transit, not the days a parcel sits with customs. International orders must ship to the country of the billing address, apart from orders within North America. Duties, VAT, GST and broker fees are the buyer's job, are not added at checkout and are paid on delivery. The shop suggests asking your customs office beforehand. A parcel that you refuse at the door may lose its refund, and a return that is accepted is reduced by the shipping costs of the parcel.
| At a glance | OmneDiem |
|---|---|
| US standard (USPS) | 7 business days after shipping |
| UPS Ground | 3 to 5 business days |
| International (UPS Worldwide Expedited) | 7 to 10 business days |
| Return | One bottle, 30 days from receipt |
| EU cooling-off period | 14 days |
Returns and refunds
The Satisfaction Guarantee lets you return one bottle for a full refund within 30 days of receipt. You start by calling (888) 876-5765 or emailing [email protected] to get an RMA, a return authorization. Not accepted back are perishable goods, custom products, personal care goods, sale items and gift cards. For parcels shipped into the European Union there is a 14-day right to cancel for any reason, provided the item is in the condition you received it.
Approved refunds go to the original payment method within 10 business days after the shop has inspected the return. If more than 15 business days have passed since approval, write to [email protected]. Check a delivery as soon as it arrives and report damaged or wrong items immediately. The phone line is open Monday to Thursday 9am to 4pm and Friday 9am to 2:30pm Eastern Time.
Cashback at OmneDiem
Open the OmneDiem page at daily cashback, check the current rate (12.5%) and press the shop button. Order in the same visit. The cashback appears as open in your free account and turns confirmed after the shop has reported the order. A returned bottle reduces the cashback by its share.
As of October 2026.