Levothyroxine Sodium Transdermal Pen (6mL)

A transdermal pen is a simple way to give your pet medicine through their skin—usually used for cats by applying gel to the inside of their ear.

Step-by-Step:

1. Get the pen ready – Twist the pen to dispense a small amount of gel. If it’s your first time, you will need to “prime” it first (the gel should be flush with the edge of the tip)
2. Wear gloves – Always use a disposable glove or finger cot so the medication doesn’t absorb into your skin.
3. Twist to dose – Follow the pen’s directions (like two full twists) to get the right amount of gel out. Always click in a clockwise direction, clicking counter-clockwise will stop you
4. Pick the spot – Apply to a hairless area, usually the inside of your cat’s ear. Make sure the area is clean and dry.
5. Apply the gel – Dab the gel directly with the pen or use your gloved finger to rub it in gently. Avoid the ear canal.
6. Let it dry – It usually dries in a minute or two. Try to keep your pet from rubbing it off.
7. Recap the pen – This keeps the medication fresh.
8. Wash your hands – Even if you wore gloves, wash thoroughly after.
9. Reward your pet – A treat helps make it a stress-free routine!
10. Store properly – Keep at room temp, away from sunlight. Track doses so you know when it’s time to refill.

Important: Only apply where your vet has directed—usually hairless areas. Never apply over fur or broken skin. Keep other pets from licking the area until it’s dry.

The uses and pharmacology described below reflect the FDA-approved labeling for this active ingredient; your veterinarian determines whether and how they apply to your animal's treatment plan.

Levothyroxine sodium is a synthetic form of the thyroid hormone T4 utilized extensively in veterinary medicine for hormonal management. It is a prescription medication available for use in dogs and horses, requiring professional guidance and monitoring by a licensed veterinarian. It is frequently considered in the context of hypothyroidism for patients presented with inappropriately low thyroid hormone levels.

Prescription only. Use only under the direction of a licensed veterinarian. This information is not a substitute for veterinary diagnosis, prescribing or monitoring. Compounded drugs are not approved by the FDA for safety or effectiveness.

At a pharmacological level, it is considered for its role in managing the body's metabolic rate by providing a source of exogenous T4 to supplement what the thyroid gland is not producing. Commonly observed effects are typically rare but may include behavioral shifts such as increased thirst, increased appetite or changes in energy levels. Because it influences the entire metabolism, your veterinarian will monitor for observational signs of hyperthyroidism, such as weight loss or hyperactivity, if the dose is too high. Owners should monitor for significant behavioral shifts and contact their veterinarian promptly with concerns.