First, let's discuss the principle and limitations of botulinum toxin for improving penile retraction:
Based on existing evidence, botulinum toxin (BoNT, also known as Botox) reduces penile retraction primarily by inducing muscle relaxation of the dartos muscle within the scrotum.
The specific mechanism is as follows:
Dartos muscle contraction causes penile retraction: The penis can retract in the flaccid state due to dartos muscle contraction. This contraction is especially noticeable in cold, stress, and exercise, and may cause embarrassment in men, even when erect length is normal and satisfactory.
Mechanism of action of botulinum toxin: Botulinum toxin is a neurotoxin that inhibits the release of acetylcholine from nerve endings. Acetylcholine is a neurotransmitter at the neuromuscular junction responsible for transmitting nerve signals to muscles, thereby causing muscle contraction. By blocking acetylcholine release, botulinum toxin can cause paralysis or relaxation of the muscle at the injection site.
Application in penile retraction treatment: In a preliminary study on treating penile retraction, researchers injected 100 units of botulinum toxin A (Botox) directly into the dartos muscle.
Result: After botulinum toxin injection, 70% of patients (7 of 10) subjectively reported a reduction in the frequency and magnitude of penile retraction, as well as improvement in flaccid penile length. Although clinical measurements were less pronounced, they also showed improvement, mainly through reduced retraction rather than length increase.
Temporary nature of effect: This improvement completely disappeared by the 6th month, indicating that the effect of botulinum toxin is temporary.
Therefore, the principle by which botulinum toxin reduces penile retraction lies in relaxing the overactive dartos muscle, thereby reducing the frequency and magnitude of penile retraction. This provides a non-surgical alternative for alleviating penile retraction caused by dartos muscle contraction.
Although preliminary data show some potential efficacy and safety, it should be noted that there is currently a lack of robust clinical trial data on the widespread use of botulinum toxin in treating male sexual dysfunction, and therefore its application in male sexual dysfunction has not been approved by the U.S. Food and Drug Administration (FDA). Currently, many such uses are "off-label," and more randomized controlled trial data are still needed to confirm its long-term safety and efficacy to support its broad clinical adoption.
References for this section:
1.Application of Botulinum Neurotoxin in Male Sexual Dysfunction: Where Are We Now?
2.Botulinum toxin a (Botox) for relieving penile retraction.
3.Safety and efficacy of botulinum neurotoxin in the treatment of erectile dysfunction refractory to phosphodiesterase inhibitors: Results of a randomized controlled trial.
Consultation and Injection Process & Fees at a Beijing Top-Tier Hospital Andrology Chief Physician
Outpatient days of a chief andrology physician at a Beijing top-tier hospital (December 1, 2025 - May 31, 2026)
Monday afternoon: Peking University People's Hospital (Xizhimen campus) Andrology Clinic
Tuesday afternoon: Peking University People's Hospital (Xizhimen campus) Urology Clinic (Room 323)
Tuesday afternoon: Peking University People's Hospital (Tongzhou campus) Urology Clinic
Consultation hospital: Peking University People's Hospital (Xizhimen campus) Registration fee: 80 RMB
Injection procedure (at Dr. Zhang's second practice site): Beijing Jiayuan Hospital
Medication and injection fee: 5,000 RMB
(It seems that if you are not leaving Beijing the same day, the procedure is not performed at the second practice site; because I was leaving Beijing the next day, I chose to go off-site. This may need to be confirmed during the consultation.)
Experience:
Nothing notable — just mild puncture pain during injection. One injection at the base of the penis, one on the left side, one on the right side. I could shower the same day, with no special post-operative instructions.
Procedure time: Disinfection and injection took less than 10 minutes in total.
Post-procedure notes:
1. Maintain stretching. Since I use the Phallosan daily, this was nothing special for me.
2. Lose weight. Objectively speaking, weight loss is the best and most effective method to increase external length. (The doctor also said this today, but I personally think this is limited to those who gained weight later in life — for example, I became obese as an adult due to anti-anxiety medication. For congenital/childhood obesity, there may already be buried penis, and I recommend seeing a doctor to determine whether surgical intervention is needed.)
3. Duration of effect: About six months or a little over six months; after that, you can get additional injections as needed, similar to facial cosmetic procedures.