This is a study designed to see if a low dose of Lithium treatment, taken for 2 weeks, can improve fracture healing and improve patients' function and productivity.

Despite the success of traditional treatments for broken bones (surgery, immobilization, or both) 10% of fractures do not heal or take longer than normal to heal. This can have a significant effect on a patient's function and productivity, as well as on healthcare expenditures. Very few advances in fracture healing have been made, despite the need for new approaches to fracture treatment. This study proposes a simple, economical, and non-invasive approach to complement traditional fracture treatment that could decrease healing time and reduce the incidence of delayed healing. The investigators think that this can improve health outcomes for patients and reduce health care costs for the healthcare system in general. The goal is to see if a low-dose of Lithium treatment can have a positive effect on fracture healing and can reduce pain and improve function in patients who have broken a bone.

The LiFT study is a participant, surgeon and observer blinded single-centre randomized (1:1), controlled, superiority trial with 2 parallel groups. A minimization procedure will stratify participants based on the fractured long bone (clavicle, humerus, femur or tibia/fibula) and smoking.

Participants will be randomized to 1 of 2 groups: lithium capsules or placebo. The Lithium/placebo will be taken daily for 2 weeks, starting 2 weeks after the fracture occurs (or 2 weeks after surgery if the participant is treated with surgery).

Inclusion Criteria:

1. Age 18-55 years.
2. ASA (American Society of Anesthesiologists) ≤ 2 class (healthy) prior to injury.
3. Diaphyseal fracture of the humerus, femur or combined tibia/fibula (OTA diaphyseal subclass 2A or B), and clavicle (OTA diaphyseal subclass B1 or B2), with or without nerve injury.
4. Fracture that is primarily closed or open fracture that has complete wound coverage.
5. Randomization ≤14 days from injury or surgery (for surgical patients).
6. Fractures treated surgically or nonsurgically by endochondral/secondary bone healing.
7. For surgical patients, surgery must be within 14 days of injury.

Exclusion Criteria:

1. Currently pregnant or breastfeeding.
2. Any past or current malignancy that, in the opinion of an investigator, is not medically controlled.
3. Metabolic bone disease based on clinical history that, in the opinion of an investigator, is not medically controlled.
4. Autoimmune disease that, in the opinion of an investigator, is not medically controlled.
5. Hypothyroidism based on clinical history that, in the opinion of an investigator, is not medically controlled.
6. Renal impairment based on clinical history.
7. Past allergy or adverse reaction to Lithium.
8. Lactose intolerance.
9. Fractures surgically treated with absolute stability/primary bone healing.
10. Isolated tibia or isolated fibula fracture.
11. Currently taking Lithium or anti-psychotic or anti-seizure medication for the treatment of these conditions or at the discretion of an investigator.
12. Inability to comply with study protocol, in the opinion of the investigator(s).
13. Participation in another interventional clinical trial, at the discretion of the principal investigator.
14. Use of concomitant ultrasound or other bone stimulation device.