Supplement email marketing: reorder timing, subscriptions and what you can say

Why supplement email marketing is really a timing problem

Supplements are a habit product. People stop when the routine breaks, and a missed week is how a customer quietly churns. But you know what they bought, how many servings were in it and when it shipped. That's enough to predict when they'll run out.

Most supplement brands I look at spend their energy on campaigns. The reorder flow, the email that pays for everything else, is missing or uses one delay for every product. If your product runs out, build the reorder flow before anything else. I go deeper on the build itself in my guide to the Klaviyo replenishment flow.

How should you time reorder emails for 30, 60 and 90-day supplies?

Start with the servings in the bottle, then pull the first email forward so a new bottle can arrive before the old one is empty. Here's where I'd start before you have your own data:

These are starting points, not rules. Once you have a few months of orders, pull the median days between first and second order for each product and move the first email about a week ahead of it. I break down that math step by step in replenishment email timing.

The first email should be easy: "You're probably getting low. Here's a one-click reorder." The second adds a reason, like a subscribe option or a bundle. The last one checks in: "Still taking it? Want to switch to a different size?"

What about multi-bottle orders?

This is where a lot of reorder flows break. A customer who buys three 30-day bottles isn't due for 90 days. If your flow only looks at the product and not the quantity, it emails them on day 21 asking them to restock while two full bottles sit in their cabinet.

That teaches them to ignore your reorder emails, including the one that matters.

Here's how I'd set it up:

• Split the flow by quantity, so a 3-bottle order gets the 90-day timing.
• Or treat multi-bottle packs as their own product with their own delay.
• Watch for early reorders. If a chunk of people reorder well before the bottle should be empty, they may be sharing it or doubling up, and a larger size is worth offering.

Subscribers and one-time buyers need different emails

Don't put subscribers in the same reorder flow as one-time buyers. A subscriber getting "time to reorder!" when their order ships automatically is confusing at best and causes double orders at worst.

One-time buyers get the reorder reminder above. Somewhere in that sequence, give them a reason to subscribe: lower price per bottle, free shipping, never running out. Ask once or twice, not every email.

Subscribers get a heads-up before the next charge. It looks like a service email, but it's a revenue email: the moment they can add a product, swap a flavor or size up.

The closest example from my own portfolio is a subscription wellness brand. Its "your order is coming up" subscription reminder made $47,321 in one month, 74% of all its flow revenue. And in a month when store revenue fell 37% and new customers dropped from 1,657 to 223, email's share of revenue went from 41% to 53%. The customers already on the calendar kept buying when new ones dried up.

A pre-charge reminder also means nobody gets billed without warning, which is a lot better than finding out through an angry reply or a chargeback. Give people a skip button. A skipped month beats a cancelled subscription.

What can you say in a supplement email?

I'm not a lawyer, and you should run your claims by one who knows supplements. But the basics are worth knowing before you write a single email.

The FTC's Health Products Compliance Guidance says health claims need "competent and reliable scientific evidence," and that you're responsible for what an ad implies, not just what it says outright. It judges the "net impression" of the whole piece. A few practical takeaways for email:

• Don't say or hint that your product treats, cures or prevents a disease.
• Have the evidence before you send the claim, not after someone asks.
• A glowing customer review is still a claim. If it describes results most people won't get, you can't use it as if they will.
• A disclaimer in the footer won't fix an email that misleads in the body.

The good news is that reorder emails don't need big claims. "You're running low" and "here's how to never run out" are about convenience, not health. That's another reason the reorder flow is where I'd put your effort.

What should you measure?

Skip open rates. Apple Mail auto-opens make them close to useless, so judge emails by clicks and revenue.

For a supplement brand, I'd watch:

• Revenue per recipient on the reorder flow, compared to your campaigns.
• Days between first and second order, by product and supply size.
• The share of first-time buyers who place a second order within their supply length plus two weeks.
• Subscription skips versus cancellations after the pre-charge reminder.

If the second-order rate climbs and the gap between orders shrinks, the flow is working. For the bigger picture on getting second and third orders, see my repeat purchase email strategy.

Where these numbers come from

The $2.23 per person figure comes from a pooled look at 4 consumable brands, 2,897 campaigns and $17.7M in email revenue. Only 2 of the 4 had a replenishment flow built. It's a small sample, so treat it as directional. The subscription numbers are from one subscription wellness brand.

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WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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