RE Botanicals' headline offer right now is the Back to School Sale with 40% off site-wide, which covers most shopping situations and represents the best value for the majority of customers. However, several other deals are running at the same time, and which one saves you the most money depends on how much you're spending and whether you're a new customer.
For a small basket under $50: If you're a first time customer, sign up to the newsletter for special offers and promotions to potentially unlock additional discounts on top of what's available to everyone else. Existing customers should go straight to the 40% off site-wide sale, which will save significantly more than the free shipping offer on smaller purchases.
For a basket between $50 and $100: The Back to School Sale's 40% discount remains your best option here. At this basket size, 40% off will save you $20 to $40 depending on the exact total, which far outpaces the free shipping offer (typically a $5 to $10 value on standard shipping).
For a basket over $100: The Back to School Sale with 40% off site-wide continues to deliver the strongest savings at this spend level. On a $100 basket, you're looking at $40 in savings; on $200, you'll save $80. The 20% Off Your Purchase deal and Up to 50% Off Selected Products will save less than the full site-wide discount unless you're buying only from the discounted product selection in that second offer.
If you're buying only sale or selected items: Check whether the Up to 50% Off Selected Products deal covers the specific items in your basket. If the selection doesn't include what you want, the 40% off site-wide sale applies to everything and may save you more overall.
Only one offer applies at checkout, so compare what each option saves on your exact basket contents before you complete your purchase. The 40% off site-wide sale will work for most shoppers, but on very large orders or if you're restricted to only selected products, checking the math against the 20% and selective 50% off deals will confirm which produces the biggest saving.