What did @drdrewtimmermans actually say?
The claim is straightforward: injecting peptides like BPC-157 or TB-500 subcutaneously over a painful area does not send that peptide directly into the underlying damaged tissue. According to the creator, the peptide gets absorbed into blood and lymphatic vessels in the subcutaneous layer and circulates systemically. He calls the belief that local injection equals local targeting "broscience," and argues there is "really no difference between injecting in the abdomen subcutaneously and over your area of pain." He also says local injection is not harmful, just misguided, and that his concern is people injecting in awkward or painful spots unnecessarily.
The video is clearly aimed at harm reduction and practical guidance. The creator is not claiming peptides don't work. He is making a narrower pharmacokinetic argument: subcutaneous absorption is systemic, not local. That is a legitimate distinction worth examining carefully.
Does the science back this up?
Mostly, yes. The subcutaneous pharmacokinetics of peptides are well-documented, and the general principle holds. Subcutaneous injections are absorbed through local capillaries and lymphatics, entering systemic circulation rather than diffusing directly into deeper anatomical structures. There is no credible evidence that subcutaneous peptide injection over a joint creates a meaningful local concentration gradient in that joint or tendon.
Studies on subcutaneous drug absorption, including work by Supersaxo et al. (1990, Pharmaceutical Research), showed that peptide molecular weight and lipophilicity govern whether absorption is primarily capillary or lymphatic, not injection site proximity to a target tissue. BPC-157 specifically has been studied almost exclusively in rodent models via intraperitoneal or oral routes (Sikiric et al., 2018, Current Pharmaceutical Design), and human pharmacokinetic data on subcutaneous BPC-157 is essentially nonexistent in peer-reviewed literature. GHK-Cu absorption data is similarly sparse for injected forms. So while the general pharmacokinetic argument is sound, applying it with certainty to these specific peptides in humans requires some intellectual honesty about the limits of the data.
What did they get wrong (or right)?
He got the core pharmacokinetic principle right. Subcutaneous injections do not tunnel through fascia and muscle to reach a specific tendon or joint. That part is not controversial among pharmacologists. Credit where it is due.
Where the argument oversimplifies is the absolute claim that there is "really no difference" between any two subcutaneous injection sites for these peptides. That is stronger than the evidence supports. Subcutaneous tissue varies in vascularity, adipose thickness, and lymphatic density by body region, which can affect absorption rate and peak plasma concentration, as documented in insulin pharmacokinetic research (Koivisto and Felig, 1980, New England Journal of Medicine). Whether those regional differences matter clinically for BPC-157 or GHK-Cu is unknown because the human data simply does not exist yet.
He is also correct that injecting in the neck, hands, or low back introduces unnecessary discomfort and technical difficulty if the systemic distribution is the same. That practical point is well-taken and probably the most useful thing in the video for a general audience.
What should you actually know?
If you are using peptide therapy through a regulated telehealth provider, the injection site guidance you receive should be based on practical safety and comfort, not on a belief that proximity to pain equals targeted delivery. Subcutaneous injections are absorbed systemically. The abdominal wall is a preferred site in many protocols precisely because it is accessible, relatively painless, and has consistent subcutaneous tissue depth.
It is also worth knowing what the evidence base actually looks like for these peptides. BPC-157 has a substantial rodent literature suggesting effects on tendon, muscle, and gut healing, but human clinical trial data is limited and the regulatory status of compounded BPC-157 has been a moving target in the United States. TB-500, or thymosin beta-4, has more human research context but still lacks large controlled trials for the recovery applications commonly discussed online. Anyone making treatment decisions based on peptide therapy should do so in consultation with a licensed provider who can assess individual risk, not based on social media pharmacokinetics lessons alone.
The bottom line: the creator's main claim is pharmacologically reasonable and probably helpful for reducing unnecessary injection-site anxiety. But the confidence with which it is stated slightly outpaces the available human data on these specific peptides.