There's a Forteo savings card available directly from the manufacturer. I believe you can apply for another when the calendar year rolls around.

You'll find all of the info here: https://www.forteo.com/savings-and-support

Except from the that page link:
MONTHLY AND ANNUAL MAXIMUM SAVINGS:
For patients with commercial drug insurance coverage for Forteo: You must have commercial drug insurance that covers Forteo and a prescription consistent with FDA-approved product labeling to pay as little as $4 for a 1-month prescription fill of Forteo. Month is defined as 28-days. Card savings are subject to a maximum monthly savings of wholesale acquisition cost plus usual and customary pharmacy charges and separate maximum annual savings of up to $9,450 per calendar year. Card may be used for a maximum of up to 13 prescription fills per calendar year. Subject to Lilly USA, LLC’s (“Lilly”) right to terminate, rescind, revoke, or amend Card eligibility criteria and/or Card terms and conditions which may occur at Lilly’s sole discretion, without notice, and for any reason, Card expires and savings end on 12/31/2024.