- TRT gels are a widely used testosterone formulation to restore testosterone levels.
- TRT gels take time to absorb, contact with the application site can transfer the gel onto others.
- To prevent secondary transfer, there are practical tips you can adopt to minimise risk.
- Healthcare professionals should inform patients of the post-application measures to avoid risk.
TRT and secondary transfer risk
If you have low testosterone and symptoms (also known as hypogonadism), your doctor may prescribe you testosterone replacement therapy (TRT).1 A popular form of TRT is transdermal gel, with the benefit of a topical, less invasive method of application.2 However, a common concern for patients is the risk of secondary transfer.
In this article, we’ll explore whether secondary transfer risk is a valid concern, and some practical steps you can take to reduce your risk.
What are TRT gels?
Transdermal gels are a popular form of TRT because they are easy to use and painless. They have minimal side effects with the most commonly reported being itchy, irritated skin around the area the gel was applied.3
TRT gel involves rubbing testosterone onto your skin, often the upper arms or shoulder, and waiting for it to be absorbed.4 This method helps you return your testosterone back to healthy levels.5 TRT gels can noticeably improve your quality of life but a common concern is the risk of secondary transfer.6
What is secondary transfer of testosterone?
Secondary transfer of testosterone is the unintended transfer of testosterone from adult men receiving gel to others around them. This process is a recognised safety risk due to the unwelcome impact additional testosterone can have on women and children in particular.7
What’s the risk with secondary transfer of testosterone?
The risks of testosterone exposure for women include the development of acne, menstrual disruption, and changes in body hair distribution. Those pregnant risk harming the foetus. For children, testosterone exposure can cause the development of pubic hair, increased libido and enlargement of sex organs, and aggression.7
How does secondary transfer of testosterone happen?
Testosterone transfer occurs because not all of the testosterone applied to the skin is absorbed and metabolised straight away, meaning a residue of the hormone remains on the surface of the skin.7,8 Because absorption takes time, any contact between the areas of application (upper arm, thighs or abdomen) and the skin of another individual soon after applying the gel can lead to the transfer of testosterone.7
Some gels require you to rub the formulation onto your skin yourself. This means you may have a residue of testosterone on your hands following the application of the gel. Again, if someone were to come into contact with the area of skin exposed to testosterone, then it may transfer onto another individual.4,9
Should I be worried about secondary transfer of testosterone?
It’s important to remain cautious and take the necessary measures to reduce the risk. If post-application measures are not taken, adverse effects may occur.7
In one study exploring the impact of testosterone transfer, direct skin-to-skin contact led to increases of testosterone of up to 185% over normal levels in women, with the risk of transfer still present 12 hours after application by the man. The study also discovered that using a t-shirt could effectively reduce the risk of transfer by almost 50%.10
Data from the FDA show that transfer to women makes up 40% of reported cases, suggesting the phenomenon is prevalent in children too.7 Data for the child population is limited due to ethical concerns.
Can testosterone gel transfer after it dries?
Provided that you adhere to the recommended drying time, which can vary between gels, there should be minimal risk of secondary transfer. However, be sure to follow the steps discussed below to ensure you are doing everything you can to reduce the risk. The recommended drying time can be found on your patient leaflet that came with your testosterone gel.
What steps can I take to avoid secondary transfer risk?
Wear clothing over the application area
After allowing for adequate drying time (read through the instructions of your testosterone gel), practical measures such as covering the applied area with clothing will minimise the risk of secondary transfer.10
If you are not using a hands-free gel, ensure you thoroughly wash your hands after use
There are a variety of testosterone gels each with different application methods. Some require you to rub the gel with the palm of your hands, and others are designed to reduce your risk of secondary transfer through hands-free application, allowing you to rub the gel onto your skin without using your hands, eliminating one of the potential routes of secondary transfer.11
If your partner is rubbing testosterone gel in for you, make sure they use gloves. If you rub the gel in yourself, then make sure to wash your hands immediately afterwards.4,9
For doctors, support your patients to minimise risk
Prevention should begin with healthcare professionals educating patients on the practical steps to minimise transfer risk. Some patients are unlikely to even consider secondary transfer unless forewarned, while others may arrive loaded with concerns. By alerting patients to the facts surrounding secondary transfer, healthcare professionals can instil caution in patients and help support them with practical strategies to reduce the risk.
Closing the conversation
TRT is not a dangerous procedure, and men with hypogonadism routinely receive treatment without any issues. However, you should ensure you carefully follow the correct steps to minimise secondary exposure to women and children.
- Jayasena C, et al. Clinical Endocrinology 2022;96:200–219.
- Čeponis J, et al. A. (eds) Testosterone. Springer, Cham 2017;https://doi.org/10.1007/978-3-319-46086-4_11.
- Shoskes, et al. Transl Androl Urol. 2016; 5(6): 834–843.
- Testavan® SmPc.
- Osterberg EC, et al. Indian J Urol. 2014;(1):2–7.
- Behre HM, et al. Aging Male 2012;15(4):198–207.
- Miller MG, et al. Current Medical Research and Opinion 2012;28(2):267–269.
- Swerdloff RS, et al. The Journal of Clinical Endocrinology & Metabolism 2000;85(12): 4500–4510.
- Testogel® SmPc.
- Stahlman J, et al. Current Medical Research and Opinion 2012;28:2:291–301.
- Kirby M, et al. Expert Review of Endocrinology & Metabolism 2020;15(4):DOI: 10.1080/17446651.2020.1773259.