Pete's Picks · Updated Oct 16

Best Smart Scale for Body Composition: Four Picks

Q: Are smart scales accurate for muscle mass?

For weight, yes. For fat and muscle, a hospital study found errors of several kilograms against DEXA, and the authors said smart scales should not replace DEXA. Use them for trends.

Q: Renpho or Withings: which is better?

Renpho offers eight-electrode scales with handles. Withings has a polished app and an eight-electrode Body Scan. We found no independent study comparing their accuracy.

Weight is the accurate part. Muscle is a trend until you get a DEXA.

Pete's #1: Renpho MorphoScan Base

By Peptide Pete · Updated Oct 16

Fact-checked against Frija-Masson 2021 and the STEP-1 body-composition note.

4 scales
DEXA is the trial method
No dollar figures

Reader-supported. We may earn from links. How that works

This page includes affiliate links. If you buy through them, we earn a commission at no extra cost to you. As an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

Renpho MorphoScan Base

Best muscle trend: a handle, so the current isn't only in your legs.

Pete's #1 pick · 9.5/10

Check Today's Price on AmazonAs an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

The short answer

On a GLP-1 the question stops being how much you lost. It becomes how much of it was lean tissue. STEP-1 used DEXA for that split. A home scale can weigh you and then estimate the rest.

I ranked handles above feet-only scales, because feet-only current misses the trunk. I didn't stand on these. The scores are the rubric, and they're not a lab.

Picks at a glance

Compare them

Swipe for more

Product	Pete Score	Trend	Easy	Segmental	Extras	Listing
Renpho MorphoScan Base	9.5	10	9	10	8	Check price
Withings Body Scan	9.0	9	8	10	9	Check price
Withings Body Smart	8.0	8	9	7	8	Check price
Renpho Elis 2X	7.9	8	9	7	7	Check price

How I ranked them

Useful trend (35%). A number you can compare next month sits at the top of the 7.8 to 9.6 band. A one-off party trick sits at the bottom of that band.
Easy to live with (25%). You'll use the simple one. A scale you dread sits lower, still inside this page's band.
Segmental (25%). A handle sits at the top of the band. Feet-only sits at the bottom of it.
Extras (15%). An ECG and extra profiles help some people. They don't answer the muscle question by themselves.

I didn't rank a clinic DEXA as a product. BodySpec is named in the article as a scan option, with no buy button.

1Best for people who want a muscle trend

Renpho MorphoScan Base

Person holding the MorphoScan handle while standing on the scale

9.5

The handle makes the trend worth logging.

Best for: you want arm, leg and trunk estimates between real scans.

Skip it if: you want a measurement a trial would recognize. That's a DEXA, not a bathroom scale.

8 electrodes plus handle
Segmental muscle
App profiles

Pete's take

I'd buy the handle, not the brand story. Foot-only scales guess the top half of you. This one sends the current through your arms and trunk, which is the part people stop training. Frija-Masson and colleagues still found fat-mass misses of a few kilograms against DEXA, so I wouldn't call the muscle number a measurement. I'd watch the direction once a week and book a scan when the trend looks ugly.

Score breakdown

Trend 10 · Easy 9 · Segmental 10 · Extras 8

Full specs

8 electrodes plus handle
Segmental muscle
App profiles

More pros and cons

The handle sends current through your arms and trunk, so the trend isn't only your legs.
Skeletal muscle by body part is on the feature list, which is the number I'd watch between scans.
You can step on it at home, which you'll do more often than you'll book a scan.

Frija-Masson still found fat-mass misses of a few kilograms against DEXA, so the number is an estimate.
I didn't step on this unit for this update.

Check Today's Price on AmazonAs an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

2Best for people who want segmental readings plus an ECG

Withings Body Scan

9.0

Segmental body composition plus an ECG, which is more machine than most people need.

Best for: you already live in the Withings app and want regions plus a heart-rhythm check.

Skip it if: you only want a muscle trend. You're paying for features this ranking doesn't require.

Handle
Segmental body composition
ECG

Pete's take

I like that Withings puts a handle on it. I don't like how easy it is to treat the ECG as proof the fat number is true. The same hospital comparison that worries me about every smart scale still applies here. Buy this if you want one app for weight, regions and a rhythm strip. If you only want muscle direction, the MorphoScan does that job with less going on.

Score breakdown

Trend 9 · Easy 8 · Segmental 10 · Extras 9

Full specs

Handle
Segmental body composition
ECG

More pros and cons

The handle puts arm, leg and trunk estimates on the table, same job as the MorphoScan.
The ECG is a real extra if your prescriber wants a rhythm strip in the same app.
Household profiles live in Withings, so a shared scale doesn't start from zero.

The ECG doesn't turn the body-fat number into a DEXA result.
It's more device than a weekly muscle check needs.

Check Today's Price on AmazonAs an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

3Best for people who want a simple Withings weigh-in

Withings Body Smart

8.0

A tidy Withings weigh-in, without a handle.

Best for: you want weight and a body-fat trend in the Withings app.

Skip it if: you're chasing arm and trunk muscle. There's no handle.

Feet only
Body fat percent
Weight to 50 g

Pete's take

I'd buy this for the weight, and I'd treat the body-fat percent as a rough trend. Smart scales are decent at weight and sloppy at fat, which is what Frija-Masson found against DEXA. The Withings app is why Easy sits high. Segmental sits at the bottom of this page because there's no handle. If your worry is muscle in the arms, this is the wrong box. If your worry is whether Tuesday's weight is real, it's enough.

Score breakdown

Trend 8 · Easy 9 · Segmental 7 · Extras 8

Full specs

Feet only
Body fat percent
Weight to 50 g

More pros and cons

It lives in the Withings app, so the weigh-in shows up next to the rest of the household log.
Weight is the part smart scales do well, and that's the number I'd trust on a Tuesday.
It's less gadget than the Body Scan, which makes a daily step-on more likely.

It's feet only, so arms and trunk stay a model.
The body-fat percent is still an estimate against a DEXA.

Check Today's Price on AmazonAs an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

4Best for people on a tight setup

Renpho Elis 2X

7.9

Fine for weight, weak for where the muscle went.

Best for: you want a daily weigh-in and you won't pretend the fat percent is a scan.

Skip it if: you're trying to see arm or trunk muscle. Feet-only current can't tell you that.

Feet only
Muscle mass on the display
App profiles

Pete's take

I wouldn't hand this to someone scared they're losing muscle in their upper body. The current stays in the legs and the rest is a model. It's fine as a weight log. I've watched people treat a feet-only fat percent like a DEXA printout, and that's how you talk yourself into the wrong plan. If the question is muscle by region, skip it and get a handle.

Score breakdown

Trend 8 · Easy 9 · Segmental 7 · Extras 7

Full specs

Feet only
Muscle mass on the display
App profiles

More pros and cons

It's simple to step on, which is how a daily weight log actually happens.
A muscle-mass figure shows on the display, so you don't need the app for the rough number.
It's enough when weight is the only question you're asking.

There's no handle, so arms and trunk are a model, not a reading.
A muscle percent from the legs is a rough trend at best.

Check Today's Price on AmazonAs an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

At a glance

1 Renpho MorphoScan Base

Best for people who want a muscle trend

Pete Score 9.5/10

8 electrodes plus handle
Segmental muscle
App profiles

2 Withings Body Scan

Best for people who want segmental readings plus an ECG

Pete Score 9.0/10

Handle
Segmental body composition
ECG

3 Withings Body Smart

Best for people who want a simple Withings weigh-in

Pete Score 8.0/10

Feet only
Body fat percent
Weight to 50 g

4 Renpho Elis 2X

Best for people on a tight setup

Pete Score 7.9/10

Feet only
Muscle mass on the display
App profiles

References: 4 · Scales compared: 6 · Status as of Oct 10, 2026

Jump to: How accurate are smart scales? · Compare the scales · The picks · When to get a DEXA · How to weigh for useful trends · Common questions

On a GLP-1 medicine, the question shifts from "how much did I lose?" to "how much of it was muscle?" Smart scales weigh you accurately and estimate the rest.

We compared six scales. A DEXA scan is the measurement when you need a real answer.

"Two years on semaglutide: the things I wish someone had told me." That r/Semaglutide post drew 148 replies, and keeping muscle came up again and again. In the STEP-1 substudy, DEXA scans showed people on semaglutide lost 19.3% of their fat mass and 9.7% of their lean mass over 68 weeks (semaglutide and muscle loss). So it makes sense to want to track both at home.

A woman steps onto a bathroom scale, shown from the feet down. — Photo: SHVETS production / Pexels

How accurate are smart scales?

A French hospital study weighed patients on one of three smart scales right after a DEXA scan, including a Withings model (Frija-Masson 2021, PMID 33929337).

Weight: accurate. Median errors were 0 to 0.3 kg.
Fat mass: underestimated. Median errors were 2.2 to 4.4 kg below DEXA, with wide spread between people.
Muscle mass: errors of a similar size.

The authors concluded that smart scales "are not accurate for body composition and should not replace DEXA in patient care." That study tested older models, so newer scales may do better, but we found no independent study showing it.

In practice, trust the weight and treat body-fat and muscle numbers as a trend line under the same conditions, not as a measurement.

Why electrodes matter. Smart scales estimate body composition by sending a small current through the body (bioelectrical impedance). Foot-only scales send it mainly through the legs. Scales with a handle, often called eight-electrode scales, also read the arms and trunk, and many give arm, leg and trunk estimates.

When to get a DEXA scan

On this page

Accurate are smart scales?
To get a DEXA scan
To weigh for useful trends
Questions
Sources

Lean mass on DEXA includes water and organs as well as muscle, so even DEXA estimates muscle. It is far closer than a scale.

A woman in workout clothes holds a water bottle and a rolled yoga mat in a park. — Photo: MART PRODUCTION / Pexels

How to weigh for useful trends

Same time each day, ideally after waking and using the bathroom, before eating or drinking.
Bare feet, dry skin, the same spot on a hard floor.
Look at weekly averages, not single days. Hydration shifts body-fat and muscle estimates.
Pair the scale with a strength log. Lifting the same or more is a better sign of kept muscle than a scale's muscle percentage.

Common questions

What is the best smart scale for body composition?

For tracking muscle and fat trends, the Renpho MorphoScan Base, an eight-electrode scale with a handle. For a budget pick, the Renpho Elis 2X.

Are smart scales accurate for muscle mass?

For weight, yes. For fat and muscle, a hospital study found errors of several kilograms against DEXA, and the authors said smart scales should not replace DEXA. Use them for trends.

Should I get a DEXA scan on Ozempic?

A DEXA scan is the most practical way to measure lean and fat mass, and it is how the semaglutide trials measured them. Ask your prescriber whether a baseline and follow-up scan makes sense for you.

How much does a DEXA scan cost?

BodySpec lists body-composition scans in the cities it serves. The price depends on the city, and I am not quoting it here. Your doctor can also order a DEXA.

Renpho or Withings: which is better?

Renpho offers eight-electrode scales with handles. Withings has a polished app and an eight-electrode Body Scan. We found no independent study comparing their accuracy.

Why does my smart scale's muscle number change so much?

Bioimpedance readings shift with hydration, meals, exercise and skin moisture. Weigh at the same time under the same conditions, and watch weekly averages.

If I could only buy one

If I could only buy one, it's the MorphoScan. The handle is the difference that matters on this page.

Best for people who want a muscle trend: Renpho MorphoScan Base

Check Today's Price on AmazonAs an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

If you want an ECG too, get Withings Body Scan.
If you only want weight in a Withings app, get Withings Body Smart.

What changed: Oct 16, 2026. Pete Scores now sit between 7.8 and 9.6. Body Scan stays above the feet-only scales.

This page includes affiliate links. If you buy through them, we earn a commission at no extra cost to you. As an Amazon Associate, Straight Up Peptides earns from qualifying purchases.

Research information, not medical advice. Scale and DEXA readings do not diagnose anything. Talk to your prescriber about changes in weight, strength or energy.

Sources, methodology, and changes

Methodology. Literature search on 2026-10-10: PubMed (smart scale, bioelectrical impedance, DEXA, accuracy). We compared six smart scales on Amazon US listings for electrodes, displayed metrics and price on October 10, 2026, and checked BodySpec's published starting price the same day. We did not test any scale. Reader quotes come from Reddit threads collected for our reader research.

Primary sources.

Frija-Masson J et al., 2021, JMIR mHealth uHealth. Accuracy of smart scales on weight and body composition: PMID 33929337
STEP-1 body-composition substudy, J Endocr Soc 2021;5(Suppl 1):A16-A17 (conference abstract), summarized on semaglutide and muscle loss
Mozaffarian D et al., 2025, joint GLP-1 nutrition advisory: PMID 40673264
BodySpec pricing page, checked Oct 10, 2026
Amazon US listings, Oct 10, 2026: B0F18PQH6N, B0FJFL8KP4, B0C6XJ1C1W, B0C3JNJPZ7, B0CZTL6Q5G, B01NALRONX, B072C4XB3G

Changes. Oct 10, 2026: first published. Oct 17, 2026: shortened the top of the page so the product photo shows on a phone.

Keep reading

How we research

We cite the study, registry record or label behind each finding. Read our methods

Spotted a mistake?

Send us the source and we will check it. Request a correction