The post was removed following the complaints and the store's franchisee posted a personal apology.
"I absolutely do care about people with allergies and made an error in judgment with this comment," the apology reads.
"I am embarrassed and disappointed I made this error. My comment in no way reflects the attitude of Boost."
Boost Juice issued its own apology, telling
Fairfax Media the company takes the concerns of the allergy community seriously and stating the Cronulla franchisee had been spoken to about the unacceptable post.
"The partner now understands the insensitivity of their post and is genuinely remorseful," the statement reads.
"We take the severity of anaphylaxis extremely seriously and the safety of our customers is our top priority. This campaign, and all campaign collateral (including in-store signage) has been designed to make it overtly clear that we have peanuts in-store so customers are aware that we are not currently a nut free environment.
"Whilst this is not the first time we have had peanuts in store (we previously sold a peanut butter protein ball), this is the first time we have used peanut butter in a smoothie range.
"In light of this, we have taken significant measures to ensure the Peanut Butter, and all equipment used in the making of the Peanut Butter smoothies, is used, stored and cleaned separately to equipment used to make all other Boost Juice beverages.
"The greatest care has been taken to ensure cross contamination is minimised, including the extensive training of staff and appropriate warnings both in-store, online and in our app."
Allergy and Anaphylaxis Australia has expressed disappointment, in a post titled "Boost Juice FAIL", that it was not contacted for advice before the campaign went live.
With contamination a major concern for allergy sufferers, some parents of children with allergies have stated they won't be visiting Boost Juice.