These and other strategic enhancements helped us drive 31% revenue growth and 153% earnings-per-share growth in the first quarter.
In fact, Euromonitor recently named Nu Skin the world's #1 beauty device systems brand for the fourth consecutive year.
We're reaching a larger and younger demographic, and the business continues to gain momentum, with 34% customer growth and 22% and sales leader growth in the first quarter.
I would like to highlight the growth in our manufacturing segment, which achieved record results and reported 69% revenue growth.
The midpoint of our adjusted guidance points to growth of about 10% for revenue and 15% for earnings per share.
This category is nearly $7 billion and is projected to grow more than 20% annually between now and 2030.
As Ritch mentioned, this is the fourth consecutive year Euromonitor has ranked Nu Skin as the world's #1 beauty device systems brand.
For us, this shift has resulted in more than 90% of our revenue coming from online transactions, with approximately half our revenue coming from recurring customer subscription and loyalty programs.
I'm excited about the recent product launches of ageLOC Boost and Nutricentials Bioadaptives, which generated more than $35 million for the quarter in a limited number of markets.
First, we'll introduce a unique beauty-from-within product line, beginning with Beauty Focus Collagen+ with our proprietary formula aimed at disrupting the burgeoning $50 billion beauty supplement market.
A recent study of U.S. adults indicated that 88% are metabolically unhealthy.
And it all happens within a digital ecosystem that enables our affiliates to attract, connect, transact and service consumers in nearly 50 markets.
So when combined, our flexible Velocity sales compensation program, our global footprint of nearly 50 markets, our best-in-class manufacturing capabilities and our significant digital transformation, all come together with an unmatched products to empower our affiliates to build their own socially enabled beauty and wellness businesses.
This region posted first quarter constant currency revenue growth of 97% with growth in every market.
Europe, Middle East and Africa also posted significant constant currency revenue growth of 98% year-over-year as leaders embrace social commerce throughout the region.
Mainland China grew 1% in local currency this quarter with customers up 16%.
Hong Kong and Taiwan recorded a 3% constant currency decline, with Taiwan's growth being offset by continued macro challenges in Hong Kong.
Customers declined 12% due to promotional activities last year, while sales leaders grew by 7% in the quarter.
Southeast Asia's constant currency revenue declined 5%, impacted by lingering effects of COVID in certain markets.
I'd also like to highlight Japan's 11% growth in local currency during the quarter.
Q1 revenue increased 31% to $677 million, with a positive foreign currency impact of 5.7%.
Earnings per share for the quarter increased 153% to $0.91.
Gross margin for the quarter improved sequentially 80 basis points to 74.8% due to product mix and easing of air freight charges versus the past few quarters.
Gross margin was 75.7% in the prior year quarter.
Nu Skin Q1 gross margins were 77.8% against 78.1% in the prior year.
Selling expense as a percent of revenue was 40.4% compared to 39.8% in the prior year.
For the Nu Skin business, it was 43.4% compared to 42%.
General and administrative expense as a percent of revenue was 25.1% compared to 28.9% year-over-year.
I am very pleased with our operating margin for the quarter, which improved to 9.3% compared to 7.1% in the prior year quarter.
This is another strong step toward our stated goal of 13% operating margin.
The other income expense line reflects a $1.6 million gain compared to a $6.2 million expense in the prior year.
Consistent with expectations and first quarter historical trends, cash from operations was an outflow of $18.9 million.
We paid $19.3 million in dividends and continued our focus on generating shareholder value by repurchasing $50.4 million of our stock with $275.4 million remaining in authorization.
Our tax rate for the quarter was 26.5%, benefited by increased profits in the West, as I mentioned earlier.
Due to our strong first quarter results, strengthening trends and robust 2021 planned product introductions, we are increasing the top end of our annual revenue guidance by approximately $60 million and our earnings per share by $0.20.
Our 2021 annual revenue guidance is now $2.8 billion to $2.87 billion, with earnings per share of $4.05 to $4.30.
This guidance assumes a positive foreign currency impact of 3% to 4% and a tax rate of 26% to 32%.
Our second quarter revenue guidance is $680 million to $705 million, assuming a positive foreign currency impact of approximately 5%.
Q2 earnings per share guidance is $0.97 and to $1.07 and assumes a tax rate of 27% to 30%.

Summary:
Earnings per share for the quarter increased 153% to $0.91.
Our 2021 annual revenue guidance is now $2.8 billion to $2.87 billion, with earnings per share of $4.05 to $4.30.
Our second quarter revenue guidance is $680 million to $705 million, assuming a positive foreign currency impact of approximately 5%.
Q2 earnings per share guidance is $0.97 and to $1.07 and assumes a tax rate of 27% to 30%.