Lansinoh NaturalWave nipples come in extra-slow, slow, medium, and fast. The less obvious part is the code molded into the rim: 2S, 3M, and 4L identify the primary slow-to-fast progression.
Lansinoh nipple size chart
Lansinoh NaturalWave flow markings
| NaturalWave option | Rim marking | How to use the label |
|---|---|---|
| Extra-slow | Check the current package/rim | Slowest option in the current 4-count lineup |
| Slow | Size 2S | Common early starting flow |
| Medium | Size 3M | Next cue-led step after slow |
| Fast | Size 4L | Faster option for coordinated feeders who find medium too slow |
Lansinoh's current NaturalWave product page says there is no exact age when a child should switch flow. Watch feeding habits instead.
Where is the Lansinoh nipple size?
Remove the nipple from the collar and inspect the bottom rim in bright light. On current nipples, slow reads Size 2S, medium reads Size 3M, and fast reads Size 4L.
Keep replacement nipples separated by flow after cleaning if more than one child or caregiver uses the bottle system. The tiny translucent code is easy to miss during a 2 a.m. feed.
Signs to try a faster Lansinoh nipple
Lansinoh gives a useful cue: if your child sucks for a long time but cannot get milk as quickly as before, a faster nipple may help. Look for a consistent pattern across feeds rather than one off day.
Before moving from 2S to 3M or 3M to 4L:
- Check the opening and air ventilation system for residue
- Confirm the nipple is centered and seated correctly in the collar
- Rule out overtightening or damaged silicone
- Consider whether the baby is tired, congested, or distracted
Then test one adjacent flow. Our bottle nipple flow guide walks through the decision.
Signs to use a slower flow
Lansinoh says milk spilling onto the baby's neck can indicate the need for a slower nipple. Also watch for repeated gulping, coughing, hard swallowing, leaking from the mouth, pulling away, or difficulty fitting breaths between swallows.
Return to the previous flow if a new nipple causes those signs. See what too-fast bottle flow looks like. Repeated coughing or choking should be discussed with a clinician.
What bottles fit NaturalWave nipples?
Lansinoh describes NaturalWave nipples as a universal fit across its own feeding bottles, pumps, and storage products. That means the Lansinoh system—not every brand marketed as a standard neck.
Do not assume cross-brand fit. Venting and collar geometry matter even when a nipple seems to snap into place.
Cleaning NaturalWave nipples
Lansinoh says to sanitize before first use, separate the nipple after feeding, wash it in a dedicated clean basin rather than directly in the sink, rinse well, and air-dry. It also lists top-rack dishwasher and compatible steam-sanitizing methods.
The CDC similarly recommends cleaning after every feed and daily sanitizing for extra protection when a baby is under 2 months, was born prematurely, or has a weakened immune system. Read the complete CDC method.
Inspect before every use and replace damaged or weakened silicone. Do not stretch, cut, or enlarge the hole.
Compare Lansinoh with other nipple charts
- 10-brand bottle nipple flow chart
- Evenflo Balance+ markings
- Philips Avent Natural Response flows
- Dr. Brown’s nipple levels
- MAM nipple sizes
This guide is educational and does not replace individualized feeding advice.