Benefit Cosmetics has backtracked on a policy that reportedly saw NHS workers turned away for beauty treatments.
A nurse wrote on Facebook that NHS staff were being refused "on the basis that [they] work with Covid patients."
The beauty brand is now allowing key workers to receive eyebrow and eyelash treatments if they were wearing medical grade PPE when in contact with Covid patients.
A spokeswoman for the firm said it regrets "any hurt or upset caused".
Responding to the healthcare worker's post, the firm wrote earlier in the week that it was a "blanket policy" to refuse service to anyone who has been in contact "with anyone suspected of Covid or having its symptoms".
It said this was needed to "protect staff and other customers".
But other social media users lashed out on the brand's pages, with some calling for a boycott.
One doctor commented: "I have been using benefit products for many years and I will never again spend another penny with your company. Utterly shameful."
Another user wrote: "Very disappointing that you tried to exclude NHS staff after everything we have been through this past year. I will not be purchasing from this brand again after being a loyal customer for the past decade."
Current guidance from Public Health England (PHE) states that a healthcare worker wearing the correct personal protective equipment (PPE) does not count as a Covid exposure if they are caring for a suspected or confirmed case of the virus.
Others pointed out that many key workers also take regular lateral flow tests.
On Thursday, Benefit Cosmetics announced it had changed its policy.
All customers will be asked a series of "screening questions", which have now been updated, on arrival for their appointments. They include:
Have you, or members of your household, had Covid or Covid symptoms in the last 10 days?
Have you been in close contact with anyone who has Covid or Covid symptoms in the last 10 days?
Were you wearing medical grade PPE at the time?
NHS workers who have been in contact with Covid patients will be able to receive treatments, providing they were wearing full medical grade PPE and no-one else in their household has recently had coronavirus or shown symptoms.
The firm, which operates out of its own stores and concessions in John Lewis and Debenhams, was able to reopen its sites in England on Monday as lockdown restrictions eased.
A spokeswoman said: "We have been working on updating our policy in time for our services reopening this week, but it is a new process and we apologise that this has not been rolled out quickly enough.
"We would like to stress that this is in no way to discriminate against our hard working NHS, who we love dearly. Like all processes in action, ours were being tweaked and have now been updated."
She added: "We deeply regret any hurt or upset this has caused during this interim and are sorry this was not rolled out sooner."
The firm also said it was important to have policies in place for the protection of customers and staff.
Several customers praised the brand after the update and thanked the brand for apologising.