She visited the newly-opened vaccination site at the Edinburgh International Conference Centre this afternoon.
Ms Sturgeon posted a tweet showing her handing out lateral flow kits and speaking to workers at the centre.
However, she said she may not have been much help – but got good insight into the work being done to meet the demands of the booster programme.
The First Minister tweeted: “Did a (media-free) ‘volunteering’ session at the @eicc vaccine centre earlier.
“Not sure I was much help but it gave me good insight into how it all works (v efficiently) and to say a massive thank you to everyone doing truly heroic work.
“Many thanks to everyone – staff, volunteers, those being vaccinated – who spoke to me @eicc this morning, and to every member of every vaccination team across the country.
“We owe you all so much!”
During her visit on Wednesday, she helped with queue management and directing members of the public to vaccination booths.
She also staffed the recovery observation area where people rest for five minutes after receiving their jag.
Queues have been forming outside the Edinburgh International Conference Centre (EICC) all week as the coronavirus booster vaccination programme is ramped up to an unprecedented pace of delivery, with every eligible adult in Scotland being offered a top-up injection by the end of December.