These up-and-coming underwear labels are threatening to upend Victoria's Secret

Online bra retailer ThirdLove has made it possible to buy bras without having to go near a fitting room.

Shoppers are asked to complete a quiz to determine their perfect bra shape. ThirdLove then ships three bra styles out to the customer, who is then able to trial these styles for up to 30 days.

Cofounder and CEO Heidi Zak told Business Insider in September that more than 11 million women have taken the quiz, and that ThirdLove now has more than 600 million data points from this. The algorithm is getting smarter and smarter, she said.

The company came into the spotlight last month after it posted a full-page ad in The New York Times, slamming an executive from Victoria's Secret for his controversial comments about transgender and plus-size models.

New York-based online underwear startup Lively was founded by Michelle Cordeiro Grant, a former senior merchant for bras at Victoria's Secret. The brand prides itself on being a bridge between athletic wear and lingerie, which it has coined "leisurée."

Bras cost $35 and come in a mix of styles including bralettes, t-shirt bras, push-up bras, and plunge bras.

Earlier this year, Lively opened its first permanent store in New York after trialing pop-ups in Dallas and Nashville, and it announced that its products would be sold at certain Nordstrom stores and online.

Read more: A company that's taking on Victoria's Secret with $35 bras just opened its first store. Here's what it's like to shop there.

The company raised a further $6.5 million in funding in September, bringing its total to $15 million. At the time, Cordeiro Grant told TechCrunch that the company had seen 300% growth in the past year.

les girls les boys is the brainchild of Serena Rees, who founded high-end underwear label Agent Provocateur back in 1994. In 2007, Rees sold the business for £60 million (around $100 million), and it later went bankrupt in 2017.

The aesthetic of her new teen-focused label is the antithesis of Agent Provocateur. Channeling the "street-to-bed" look, the focus is on comfort and creating underwear that isn't restrictive, Rees told Business Insider. She said that she felt compelled to create the company because of the need for change in the underwear market.

J.Crew-owned Madewell launched its own underwear collection in February 2017.

Featuring a mix of panties and bralettes, the collection professes to be "unfussy, simple and well-designed and in a minimal, effortless way," Madewell's head of design, Joyce Lee, told Fashionista when the collection launched.

Madewell also started selling Lively underwear in August 2018 as a digital-only partnership. A spokesperson for Lively told Business Insider that the company is planning to roll out exclusive products with Madewell in 2019.

J.Crew launched its Intimates underwear and nightwear collection earlier this year.

The collection costs around $32 for bralettes and between $36 and $45 for underwire bras. Panties cost between $12.50 and $16.50 at full price.

J.Crew has made a concerted effort to grow its business, add new collections, and bring back customers after reporting weak sales for the last four years.

Former CEO James Brett, who stepped down last month, lowered prices, added plus-sizes, and started selling its low-cost Mercantile collection on Amazon.

His strategy seemed to be paying off, J.Crew's same-store sales numbers turned a corner in August and have continued to grow since then. They were up 4% in third-quarter earnings, which were reported in November.

Gap's latest underwear collection, Love, is focused on "comfortable basics" and launched in February.

Its ad campaign was well-received online at the time. One photo that showed a woman breastfeeding her baby went viral after being praised on Instagram.

"I have never shopped at Gap, but I will be purchasing something tonight! This is amazing!" one Instagram commenter wrote at the time.

New York-based luxury lingerie brand Journelle has gained a cult following of fans (including Gwyneth Paltrow) who shops the high-quality underwear brands it stocks, such as Stella McCartney and L'Agent.

But in 2014, the company launched its own private-label collection headed by former Victoria's Secret designer Rania Abu-Eid. It costs between $19 for a thong and $94 for an underwire bra.

The company now has three stores in New York and one in Chicago.

Everlane rolled out its new underwear collection earlier this year, which drew in a waitlist of 30,000 eager customers within the first week.

The collection includes underwear, bras, and bodysuits, all costing under $35.

Each piece is made with Supima cotton, which is grown in the US.

Online-only store True&Co, which launched in 2012, aims to make shopping for bras more straightforward with a quiz that asks shoppers a series of questions about their shape, how their bra currently fits, and what preferences they have.

From there, the store emails customers a selection of recommended bras, which they can try on at home and then return any that they don't like.

The company was acquired in 2017 by PVH Corp., the parent company of brands such as Calvin Klein and Tommy Hilfiger, for an undisclosed amount.