Every item you order comes with a second identical unit at no additional charge. Add one to your cart and the matching unit is added automatically at checkout.

No code needed. Nothing to enter, nothing to remember. The matching unit appears on your order summary before you pay.

Every product you can currently order qualifies, with no exclusions and no minimum order value. Multi-vial packs are a separate case — they are temporarily paused for the duration of the sale rather than excluded from it. See “Are 10-vial packs still available?”

You pay the listed price for one unit and receive two. That works out to half the per-unit cost on every product you can currently order.

For example, an item listed at $99.99 gets you two units for $99.99 — just under $50 per unit instead of $99.99. Your total is unchanged; the quantity doubles.

If you were waiting on our previous discount event, this replaces it. The 2 for 1 sale is the only sale running, and it stacks with Subscribe & Save and with the 10% member discount.

The offer applies to every unit in your cart, with no cap. Add two different products and you receive four units — a match for each. Add three of the same product and you receive six.

The matching unit always matches the item it doubles. It cannot be swapped for a different product.

The 2 for 1 offer stacks with Subscribe & Save. The 10% subscription discount applies to the listed price and you still receive the matching unit.

That is the lowest per-unit cost we currently offer. On a $99.99 item a subscription order is $89.99 and still includes two units — about $45 per unit, versus just under $50 without a subscription.

If you start a subscription while the 2 for 1 sale is running, the matching unit repeats on every renewal for as long as that subscription stays active — not just on your first order.

This is the main reason to subscribe now rather than later. Once the sale ends, new subscriptions renew at a single unit per shipment.

The offer applies to subscriptions started during the sale. Subscriptions already running before the sale began continue on their existing terms.

You can pause or skip a shipment without losing it. If you cancel the subscription outright the offer ends with it, and resubscribing later will not restore it.

Your matching units ship together with the items you ordered.

This offer runs for a limited time while supplies last. We have not announced an end date. Stock on individual products can run out before the sale closes.

All products are sold for laboratory research use only. Not for human consumption.