Switching between testosterone preparations is feasible and sometimes necessary. You can do this by stopping the old preparation and starting the new preparation at the next scheduled dose. There will then likely be changes to frequency and dose, depending on the preparation. This will still be based on your blood tests and tailored to you.
Blood Testing
We still strongly recommend that you take regular blood tests to make sure that you're seeing changes at the best rate, and to help prevent any side effects .
To make sure you're on the right dose, and if you want to change your dose, you can refer to this table to see which blood tests you need:
| Medication | Required Tests | Frequency |
|---|---|---|
| Testosterone alone |
| Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks. |
| Testosterone & GnRHa Blocker |
| Every 3 months for a year, then annually (unless you are on a high dose) or as advised. If you change dose, resume 3-month checks |
You can read more about blood tests here.
You can order blood tests the Hub. For a walkthrough, you can see this guide.
How to Request a Different Preparation
You can request to change your dosage or between preparations (e.g., gels and injections) through the My Medication section of your Hub account. If you want to increase your dose, please make sure your blood test results are up to date.
We have a full guide on how to do this here.
Making the Change
This table helps explain how to make the change from one preparation to another:
| Switching From and To | Approach and Timing |
|---|---|
| Sustanon or Enanthate → Gel | Stop injectable; start gel on the day the next injection would have been due. |
| Sustanon or Enanthate → Nebido (long-acting undecanoate) | Stop Sustanon/enanthate; start Nebido on the day next injection is due. |
| Gel → Sustanon/Enanthate | Stop gel; start injections next day. Start with injections every 3-4 weeks. Recheck hormone levels after the 3rd or 4th injection. If the prior gel dose was high (>40 g/day), start injection interval shorter (~3 weeks). |
| Gel → Nebido | Continue gel for first 4 weeks while Nebido reaches effective levels. Then second Nebido injection at 12 weeks, blood test ~6 weeks after that. Adjust frequency as needed. |
| Nebido → Sustanon/Enanthate | Stop Nebido; begin Sustanon/enanthate on the day next Nebido dose would have been due. Frequency ~every 4 weeks initially. Monitor; adjust based on level. |
| Nebido → Gel | Stop Nebido; start gel on the day next Nebido dose is due. If the preceding Nebido interval was long (14-26 weeks), use low-dose gel; if shorter (8-14 weeks), medium dose gel. |