TRT delivery methods: what the science says about 'best'

What did @ayub_ace actually say?

The creator is advocating for daily subcutaneous injections of testosterone cypionate at 10mg per day, using an insulin syringe to draw 5 units from a 200mg/mL vial. His pitch: this method eliminates scar tissue, oil buildup, and irritation, and may help people who are struggling with unstable levels or estrogenic side effects. He's speaking from personal experience, not a clinical background, and he's transparent about that.

To be clear on the math: 5 units on a U-100 insulin syringe equals 0.05mL. At 200mg/mL concentration, that delivers 10mg of testosterone cypionate. The arithmetic is correct. That part he got right.

Does the science back this up?

More than you might expect, actually. Daily or frequent low-dose subcutaneous testosterone injections have genuine clinical support, and this isn't just gym-bro speculation.

A 2017 study by Spratt et al. published in The Journal of Clinical Endocrinology and Metabolism found that subcutaneous testosterone enanthate produced stable serum testosterone levels with less pharmacokinetic variability than intramuscular injection. Stable levels matter because peaks and troughs in testosterone are one of the primary drivers of estrogenic side effects, particularly elevated estradiol, which arises when excess testosterone gets converted by aromatase in adipose tissue.

The logic behind daily dosing is sound. Testosterone cypionate has a half-life of approximately 8 days, but daily micro-dosing essentially keeps serum levels flat rather than creating the spike-and-crash pattern common with weekly or biweekly IM injections. Less spiking means less aromatization at peak, which means less estradiol, which is exactly the estrogenic side effect reduction he describes. A 2021 review by Ramasamy et al. in Sexual Medicine Reviews noted that subcutaneous administration is an underutilized but clinically viable route with favorable tolerability profiles.

What did they get wrong (or right)?

The scar tissue and oil buildup claims are mostly right for the sub-Q route, but he overstates them as absolute guarantees. Subcutaneous injections do carry lower risk of scar tissue compared to repeated intramuscular injections into the same site, because you're depositing a small volume into fatty tissue rather than muscle fibers. However, some individuals do develop subcutaneous nodules with daily injections, particularly if they rotate sites poorly or have lower body fat. Saying you will see "no scar tissue" and "no irritation" is a promise no one can make to a general audience.

He also doesn't mention that 70mg per week (10mg x 7 days) is a relatively low therapeutic dose. For some men, particularly those with more severe hypogonadism, this may not be sufficient to reach optimal therapeutic levels. Dose adequacy depends on individual metabolism, SHBG levels, and baseline testosterone, none of which he addresses. That omission matters when people use videos like this to self-direct their treatment.

His framing as "the best method" is personal testimony, not evidence. That said, the underlying approach is clinically defensible.

What should you actually know?

Daily sub-Q testosterone is a legitimate, evidence-supported administration method that some TRT clinics already use as a first-line protocol. The core benefits he describes, including more stable hormone levels and potentially reduced estrogenic side effects, are real and documented in the literature.

But the framing matters. This is one protocol option among several, not a universal fix. Weekly intramuscular injections remain the most common clinical standard and work well for the majority of patients. Sub-Q daily dosing requires consistent adherence, proper site rotation, and monitoring of hematocrit, estradiol, and testosterone levels. It also requires a prescription and medical oversight, both for safety and legality.

If you're experiencing instability on a standard TRT protocol, the right move is to discuss frequency and route adjustments with your prescribing provider. Insulin syringes and sub-Q injections are not something to start without guidance, even if the idea sounds simple on TikTok. Individual variation in SHBG, aromatase activity, and injection technique means outcomes vary significantly from person to person.

One more thing: the 200mg/mL concentration he references is a common compounded formulation. This is not the same as FDA-approved brand-name testosterone products, which differ in concentration and manufacturing standards. Do not assume interchangeability.