Ms Boyd said the community had not been consulted on the new model of sexual health delivery, as they should have been.
"Assumptions have been made without asking the public what they need. The move to phone consultations and GP visits is not in our view what teenagers in particular want."
Teenagers receiving sexual health checks in a GP setting did not give suitable privacy and made them feel conspicuous, especially in small towns, Ms Boyd said.
They may even avoid getting their sexual health checks.
"Our members feel this funding-based decision is an ill-considered, knee-jerk reaction to the population decline in Greymouth, without finding a 'work around' with a view to preparing for future population growth. It is cost cutting that could cost teenagers dearly."
Sexual health in small rural towns was known to be in a worse state than in urban centres, she said.
The easy-to-access, private setting of the current clinic, on the top floor of the hospital, was safe for youth to visit.
"Although the number of appointments to the nurses have dropped and this is how funding is measured, community nurses do a great deal of outreach and this is where preventative care and educating about good sexual health really pays off," Ms Boyd said.
Family Planning chief executive Jackie Edmond said the Greymouth clinic ran for seven hours a week and was half empty.
People either did not make appointments, or did not turn up.
"We had to look at making some decisions. We went through the process with the NZNO (union) and staff. We decided we would look at stopping the clinic, and setting up a virtual clinic," Ms Edmond said.
Women would be able to call up and get a prescription faxed to their pharmacy, including the 'morning after' pill. The only problem will be people first starting the contraceptive pill, who would need to be weighed and have a blood test.
She said the new "virtual clinic" could potentially reach people across the West Coast, rather than just in Greymouth at a static clinic.
One client, who has used the Family Planning services for about 15 years, said she preferred going there rather than her local GP for cervical screening and other gynaecological issues.
"It's like a one-stop-shop. I live in a small town and know most of the doctors and nurses at my local clinic. I prefer to just keep that side of my health care separate."
West Coast District Health Board interim general manager Grey-Westland, Philip Wheble, said Family Planning had recently let the board know it was planning a "service redesign".
"We are now working with them to understand how this will impact on our communities, and any increased demand on other services, including general practice," Mr Wheble said.
In 2008, the Greymouth Star reported the clinic dealt with 515 patients wanting sexual health advice, with a further 449 in Westport.
In 2014, the West Coast had 150 people diagnosed with the sexually transmitted disease chlamydia - including two under 14 years.
- Greymouth Star