iHerb currently shows the 20% off your first order promo code at the top of the page, and that is best for new customers buying regular priced items (it excludes sale products). Use the 20% off your first order code if this is your first purchase and your cart is full price. If you are buying specifically immunity products, the 22% off Immunity Support code may save you more, but it is category restricted.
Big first time order (large cart of full price items): If this is your first order and most items are full price, the 20% off your first order code applies sitewide to qualifying items and is the obvious starting point. For a $200 first order of full price items, the first order code reduces your total by $40, leaving $160. Use the 20% first order code.
If your cart is mostly immunity products: The 22% off Immunity Support code applies only to the immunity category and cannot be used with other offers. On a $100 basket made up entirely of qualifying immunity items, 22% off saves $22, leaving $78. Compare that result with the 20% first order saving for new customers to see which gives the lower total; the immunity code saves more when your cart is concentrated in that category.
If you buy supplements experts take (non sale): The 20% off supplements experts take every day code covers many vitamins, minerals and targeted formulas until 9 November 2026 and cannot be combined with other promotions. If your cart is $75 of these qualifying supplements, that code saves $15, leaving $60. Use that supplements code when the qualifying list matches most of your items.
Doctor’s Best brand purchases: Either Doctor's Best 20% codes apply only to that brand and cannot be combined with other offers. If your $100 order is all Doctor's Best, the 20% brand code saves $20, leaving $80. Use the Doctor's Best code when most of the basket is that brand.
Shopping in the app for the first time: The 15% app purchase coupon is valid only for your first app purchase. If you must buy via app and your first app cart is $60 of eligible categories, 15% saves $9, leaving $51. Choose the app coupon when the order must be placed in the app and the larger site codes do not apply.
When sale prices are lower: Sale items marked down up to 75% are automatic price cuts and the sale terms say they cannot be combined with other promotions. If a sale price on the items you want is lower than the price you would pay after any code, take the sale price.
Our records show iHerb listed 68 offers in the 12 months to November 2026 (49 codes). Percentage codes in that window typically were 20% and the biggest code seen was 30% off; our team ran 27 checkout tests across 26 offers in that period. That history means 20% codes are common, but larger codes have appeared.
When choosing, compare the final totals for the one code that applies to your basket. Most of these promo codes cannot be combined with other offers, so take whichever option leaves you with the lower final price.