Sunlighten sauna review: mPulse, Amplify and Signature compared on specs, warranty and return terms

Sunlighten sells three cabin lines, plus the lie-down Solo. The lines differ in how they heat, not in build: all of them are Basswood or Eucalyptus, with the same 7-year terms.

Every listed price is a sale price; the store shows regular prices $500 to $1,200 higher. The Amplify RED II was listed but sold out on Oct 27, 2026. The store also sells cabins that aren't in our database yet: Signature III, Amplify IV, Amplify RED III and RED IV. The larger mPulse Discover (4 seats) and Empower (5) aren't sold there either; the store has only accessory packages for them.

mPulse is the line with the most hardware. It splits infrared into separate far and mid infrared heaters and adds LED panels in red and near infrared, each controlled on its own. The Sunlighten mPulse Believe has 6 far + 5 mid-infrared heaters and 4 LED panels; the Sunlighten mPulse Aspire for one person has 3 panels, the Sunlighten mPulse Conquer for three has 5.

Amplify mixes carbon far-infrared heaters with three 500 W full-spectrum emitters. It's the only line where Sunlighten states a top temperature: 170°F, "up to", in ideal conditions. The Sunlighten Amplify RED II is the same cabin with 4 red/NIR LED panels added, $1,700 more than the Sunlighten Amplify II at store prices.

Signature is far infrared only, from carbon heaters: 8 in the Signature I, 9 in the II and 10 in the IV. Sunlighten recommends a 45–60 minute preheat, about 1°F per minute. No top temperature is published. It's also the cheaper line: the two-seat Sunlighten Signature II is $5,499 against $5,999 for the Sunlighten Amplify II.

About the red light: Sunlighten says how many LED panels each cabin has, but not their wavelengths, the number of diodes or the output. So you can't compare them with a standalone panel, where those numbers are the whole question. How far, mid and near infrared differ is on our infrared sauna guide.

None of the cabins plugs into an ordinary 15 A outlet. The one- and two-seaters (mPulse Aspire, mPulse Believe, Amplify II, Signature I, Signature II) need a dedicated 120 V 20 A circuit with a NEMA 5-20 outlet. The three- and four-seaters and the Amplify RED II need 240 V on a 20 A circuit (NEMA 6-20). If you don't have that circuit, the electrician is part of the price; have a licensed one look before you order.

Every cabin is 77.7 to 79 inches tall, and they're heavy. The two-seaters are 50.9–51.7 by 45.9–47.6 inches outside and weigh 438–529 lb in Basswood, more in Eucalyptus; the mPulse Conquer is 70.6 inches wide and 606 lb. Inside, the Signature I is 32.2 × 33.6 in, the narrowest cabin in the line.

The residential warranty is 7 years on the cabin and heaters, 3 years on the controls and 1 year on the glass door and audio. One condition is easy to miss: the sauna must be bought and activated within one year of its manufacture date. If a dealer offers you old stock, ask for that date in writing.

The return policy (checked October 16, 2026) is stricter than most. mPulse, Amplify, Signature and Solo can be returned within 30 days of delivery only in the original, unopened packaging: "Any opened saunas are unable to be returned or exchanged." Even then, Sunlighten may charge a 3% administrative fee, storage, a $499 restocking fee per cabin ($299 for a Solo System) and the return shipping, and it "reserves the right to refuse a return."

In practice you decide before you sit in it. Other brands are only a little looser: Clearlight takes a sauna back like new in its packaging and keeps 25%, and Heavenly Heat calls its 30 days an in-home trial, but the same policy excludes assembled saunas and puts return freight at $750–$1,500.

Only one model page gives a number: the Sunlighten Amplify RED II, at under 1 mG, "third-party verified", with no distance. The mPulse pages say the cabins were "third-party tested by Vitatech Electromagnetics" and give no figure. Every other page says "ultra-low EMF" and stops there.

A milligauss figure without the distance it was measured at can't be compared with anything, because the reading drops quickly as you move away from a heater. I haven't found an independent measurement of any Sunlighten cabin, so for this brand EMF is not independently measured.

Sunlighten doesn't present its saunas as medical devices. The footer of its pages reads: "Sunlighten products are considered General Wellness products, not medical devices, as defined by the Food and Drug Administration" (sunlighten.com). I also found no Sunlighten listing in the FDA's registration and 510(k) databases. Sunlighten writes a lot about health on its own site; what studies of infrared saunas actually show is on infrared sauna benefits.

On Oct 27, 2026, the brand's store listed 6 of the 9 cabins in our database, from $4,999 for the Sunlighten Signature I to $7,799 for the Sunlighten Signature IV. Those are Eucalyptus prices; the Amplify II and III also come in Basswood for $200 less. The three mPulse cabins aren't in the store, and their model pages show a "Get pricing" form. The Solo System is $2,099, on sale from $2,999. Model by model, with what to ask for in a quote: Sunlighten sauna prices.

Two things can lower what you pay. Sunlighten finances through Wells Fargo, "subject to approved credit," with no rate or term printed on its financing page. And if you know an owner, its referral program gives a new customer $200 off a cabin or $100 off the Solo System through the owner's link; the owner gets a $100 coupon for each of their first three referrals and must be a U.S. resident registered in the program. Terms read October 7, 2026.

The Solo System isn't a cabin: you lie on a heated pad under two far-infrared domes, plugged into ordinary outlets. It has no red light, reaches 150°F at the top setting by Sunlighten's own usage guide, and carries the same 7-year warranty on the domes and pad. The store lists it at $2,099, and the dome alone at $1,999. Full review: Sunlighten Solo.

We're not in Sunlighten's affiliate program: its terms bar partners from working with other infrared sauna sellers. The cabins below are from brands we link to; the order is by warranty and then price, not by any program's terms.

Two things stand out. Heavenly Heat gives 10 years on its indoor cabins against Sunlighten's 7, and the Heavenly Heat 2-Person runs off a standard 15 A outlet where every Sunlighten cabin needs a 20 A circuit. Sun Home is the closest match to the mPulse for red light, and it shows a price where the mPulse doesn't, but read its warranty section before you count on "lifetime". Clearlight gives a lifetime warranty on its cabins too; its review has the prices, and Clearlight vs Sunlighten sets the two brands side by side on wiring, red light and return fees. Sun Home's cabins against Sunlighten's: Sun Home vs Sunlighten.

One brand we don't suggest right now: Radiant Health. Every Radiant Health sauna sold through August 1, 2026 is under CPSC recall 26-784, and Sunlighten isn't on that recall's model list. How the two compare on price, warranty and returns is in the Radiant Health review.