A replenishment flow reminds customers to reorder shortly before they run out. Done well, it is the highest-leverage flow a supplement or coffee brand can build, because it meets a need the customer already has.
Step 1: calculate days of supply for every product
Start with a simple formula:
Days of supply = units in the package ÷ units used per day
A bottle of 60 capsules taken twice a day lasts 30 days. A bottle of 60 capsules taken once a day lasts 60. Put every product and size into a small table:
| Product | Typical days of supply | First reminder | Second reminder |
|---|---|---|---|
| 30-day supplement bottle | 30 | Day 21–24 | Day 30 |
| 90-day supplement bottle | 90 | Day 70–75 | Day 90 |
| 12 oz coffee bag (illustrative) | 14–21 | Day 10–14 | Day 18–21 |
These timings are starting points, not benchmarks. Your own data, and your A/B tests, decide the final numbers.
Step 2: choose the trigger and handle multi-product orders
The usual trigger is Placed Order. Create separate flows (or splits) per product or per product group, using the products in the order to decide which timing applies. If an order contains items with different durations, base the timing on the item that runs out first, or the highest-value item, and be consistent.
Treat first orders and repeat orders differently. A first-time buyer is still learning the product and may use it unevenly, so a slightly later and softer first reminder often works better than the same message sent to a long-term customer.
Step 3: exclude people who do not need the email
- Active subscribers. They will be shipped automatically; a "reorder now" email is noise and can confuse them. Exclude them with a segment or profile property synced from your subscription app.
- Customers who already reordered. Use a flow filter such as "has not placed an order since entering this flow" so someone who ordered early stops receiving reminders.
- Recent refund or support cases. Do not send a reorder reminder to someone who just asked for their money back.
Step 4: write a short sequence
- Heads-up (before run-out). Friendly, practical, one clear button to reorder. No discount.
- Run-out day. Reinforce urgency and make reordering a one-click action. For one-time buyers, offer the subscription as a convenience ("never run out").
- Gentle follow-up (after run-out). Acknowledge that they may have run out and offer help, such as a different size or a flexible subscription. If you use an incentive at all, hold it for this last step.
Step 5: cross-check with Klaviyo's predictions
Klaviyo can calculate a predicted next order date for ecommerce customers once your account has enough order history. Use it as a sanity check against your product-based timing, or as a way to fill in the gaps for customers who buy irregularly. Product knowledge should lead; the prediction supports it.
Step 6: measure the right things
- Second-order rate within a window tied to the product (for example, within 1.5× the days of supply).
- Revenue per recipient rather than open rate.
- Time to second order before and after launch.
- Subscription conversion from the run-out email.
Test one variable at a time: timing first, then offer, then creative. See the full retention playbook for where this flow fits, and how to read cohort curves to confirm the lift is real.
Tehseen Arbab
Retention and lifecycle marketer for DTC supplement and coffee brands. I led retention for a supplement brand whose monthly run-rate grew from about $500K to $700K, and I work in Klaviyo, Skio, Recharge, Meta Ads and Shopify.