Meghan Markle Effect: Prince Harry’s Fiancée’s Christmas Lunch Dress Already Sold Out!

Meghan Markle has once again proven her growing influence in fashion.

The "Suits" actress joined Queen Elizabeth II and the rest of the British royal family for the monarch's annual Christmas lunch. For the event, Markle opted to wear a black and white dress from Self Portrait, a London-based brand, People reported. The dress, dubbed as the Nightshade Midi Dress, features a mini style design with black lace top and pink and white details. It also includes a solid black skirt.

After photos of Prince Harry's fiancée wearing the dress surfaced, it sold out in stores within hours. However, for those who wish to get an outfit similar to Markle's, the brand offers other variations. Self Portrait's Payne Cutout Mini Dress and the Hudson Mini Dress feature the same style as Markle's gown. Rebecca Taylor and Elie Tahari also offer dresses with the same cut and design.

Meanwhile, Markle surpassed Kate Middleton in Lyst's Fashion Influence for 2017. The "Horrible Bosses" actress was in the fourth spot, while the Duchess of Cambridge trailed behind at the fifth spot.

"Meghan proved her royal style credentials this year, wearing heritage British brands Barbour, Hunter and Burberry," Lyst said in a statement. "She also spiked searches for lesser known labels Misha Nonoo and Finlay and Co."

Markle's influence in fashion is unquestionable, and the brands that the bride-to-be have worn over the past few months are overwhelmed. In fact, some are struggling to meet the high demand.

"The interest in the brand has been incredible," Strathberry spokesperson Leeanne Hundleby said after Markle was photographed with their bag. "The phones began ringing constantly and our visitor numbers on our website were up by around 5000 percent! It felt pretty amazing that thanks to Meghan carrying our design, people all over the world were becoming aware of Strathberry."

LINE The Label, who designed Markle's white wrap-style coat during her engagement photocall with Prince Harry, is experiencing the same struggle. "We are now dealing with the aftermath because everyone is trying to get it, but I don't want 10,000 white coats out there – it has to stay exclusive," John Muscat, president and co-founder of the brand, said.

Markle's Meghan Effect started when she made her first public appearance with Prince Harry as a couple at the Invictus Games in Toronto in September. Many deemed her influence as potent as Middleton's Kate Effect.