When it comes to fertility treatments, injectable medications—such as Follistim® (follitropin beta)—often play a crucial role. Typically, Follistim is administered using the Follistim pen, but sometimes patients or clinics choose to use U-100 insulin syringes for drawing out and administering leftover Follistim. This blog post will help you understand why a conversion chart is needed, how to use it, and what to keep in mind when injecting subcutaneously.
“While the Follistim pen is convenient, having alternatives is crucial for patients who need more flexibility in their medication approach.”
— Dr. Jane Smith, MD, Fertility Specialist
Why the Need for a Conversion Chart?
- Leftover Medication: Many patients want to use every drop of medication, especially given the costs of fertility treatments. There’s often a small amount of “overfill” in Follistim cartridges.
- Flexibility: In certain scenarios, clinics may prefer (or require) using a standard insulin syringe.
- Accuracy: The Follistim pen’s dial is designed for its own cartridges, so measuring leftover amounts with a pen might be imprecise. Using a U-100 insulin syringe—once you understand the concentration—can help approximate your desired dosage.
Read more… How to use Follistim® Insulin Syring:
Understanding the Concentration
A standard assumption is about 833 IU (International Units) of Follistim per 1 mL of fluid. This approximate concentration stems from labeled Follistim cartridges:
- 300 IU in ~0.36 mL
- 600 IU in ~0.72 mL
- 900 IU in ~1.08 mL
However, always confirm your medication’s actual concentration, as overfill volumes can vary.
Follistim-to-Insulin Syringe Conversion Chart
Below is an approximate conversion chart. Always confirm with your fertility clinic.
| Follistim (IU) | Volume (mL) | U-100 Insulin Syringe “Units” |
|---|---|---|
| 25 IU | 0.03 mL | 3 units |
| 50 IU | 0.06 mL | 6 units |
| 75 IU | 0.09 mL | 9 units |
| 100 IU | 0.12 mL | 12 units |
| 125 IU | 0.15 mL | 15 units |
| 150 IU | 0.18 mL | 18 units |
| 175 IU | 0.21 mL | 21 units |
| 200 IU | 0.24 mL | 24 units |
| 225 IU | 0.27 mL | 27 units |
| 250 IU | 0.30 mL | 30 units |
| 275 IU | 0.33 mL | 33 units |
| 300 IU | 0.36 mL | 36 units |
| 325 IU | 0.39 mL | 39 units |
| 350 IU | 0.42 mL | 42 units |
| 375 IU | 0.45 mL | 45 units |
| 400 IU | 0.48 mL | 48 units |
| 450 IU | 0.54 mL | 54 units |
| 525 IU | 0.63 mL | 63 units |
| 600 IU | 0.72 mL | 72 units |
Practical Tips for Injection
- Check Your Leftover Volume:
- If you’re drawing out leftover medication from a used Follistim pen, be aware you may have more medication than you think due to overfill.
- Use a New Needle/Syringe:
- Sterility is critical in fertility treatments. Never reuse needles or syringes.
- Rotate Injection Sites:
- Follistim is typically injected subcutaneously (into the fatty tissue). Common sites include the abdomen and upper thigh. Rotate sites to prevent irritation.
- Follow Clinic-Specific Instructions:
- Some clinics have unique reconstitution protocols that can change the concentration.
- Always confirm the exact guidelines given by your fertility nurse or doctor.
Frequently Asked Questions (FAQs)
1. Can I just rely on the Follistim pen to measure leftover medication?
The Follistim pen is designed for single-use cartridges, and leftover amounts can be difficult to measure accurately with the pen. An insulin syringe can provide a more precise volume measurement if you know the concentration.
2. Is the concentration always 833 IU/mL?
Not always. That figure is an approximation based on standard Follistim cartridges. Overfill and manufacturer variations can cause slight differences. Always double-check with your clinic to see if they have a specific dilution or measurement method.
3. What happens if I’m off by a few units or I see bubbles in the syringe?
Tiny discrepancies are common, but do your best to remove air bubbles and measure accurately. If you have concerns about dosing accuracy, consult your healthcare provider.
4. Can I reuse the insulin syringe to save money?
No. Never reuse needles or syringes. Reusing can lead to contamination and infection risks.
5. Where can I inject Follistim?
Typically, Follistim is injected subcutaneously in the lower abdomen or upper thigh. Always follow your clinic’s recommended injection sites and techniques.
A Word of Caution
All the information above serves as a general guide. Do not substitute this blog post for medical advice. Your fertility specialist knows your unique situation best and will give you precise instructions on dosage, mixing, and injection technique.
References
- Follistim® AQ Cartridge [Package Insert]. Merck & Co., Inc.
- Practice Committee of the American Society for Reproductive Medicine. (2020). Medication guidelines for ovarian stimulation in ART. Fertility and Sterility.
- Centers for Disease Control and Prevention (CDC). (2023). Injection Safety. CDC Injection Safety Website
Disclaimer:
This blog post is for educational purposes only and does not replace professional medical advice. Always consult your doctor, nurse, or pharmacist regarding your personal fertility treatment plan and any questions about medication dosages or administration techniques.
Final Thoughts
Using a standard U-100 insulin syringe to extract and measure Follistim can be a safe and effective method, provided you understand how to convert units and follow proper injection protocols. If you have any doubts, reach out to your healthcare provider for clarity and reassurance. Good luck on your fertility journey!
