What did @calxshreds actually say?
The creator is advising someone about to run testosterone alongside NPP (nandrolone phenylpropionate) for the first time. The core claim is that NPP raises progesterone, prolactin, and estrogen, and that combining masteron, 200-300mg of P5P daily, cabergoline on standby, and an aromatase inhibitor is the sensible way to manage those side effects. They also admitted, directly, that they personally got "cooked by it" recently.
To be clear about what this video is: it is unsolicited harm-reduction advice for a steroid stack that includes a controlled substance (nandrolone). It is not TRT advice in any clinical sense. Calling this category TRT is generous. This is performance-enhancing drug stacking guidance from someone who identifies as a user, not a practitioner.
Does the science back this up?
Partially, but with some significant errors buried in the explanation. The mechanism connecting 19-nor steroids like nandrolone to elevated prolactin is real, but the creator's framing of progesterone as an "anti-androgen" is inaccurate, and the P5P dose they recommend is dangerously high.
Nandrolone and other 19-nor anabolic steroids are known to elevate prolactin through their progestogenic activity at the pituitary. This is supported by clinical literature. Buvat et al. (2013, Journal of Sexual Medicine) documented hyperprolactinemia in anabolic steroid users, with 19-nor compounds specifically implicated. The connection between elevated prolactin and gynecomastia, loss of libido, and mood disruption is clinically documented. Masteron (drostanolone) does have anti-estrogenic properties due to its competitive binding at androgen receptors and some evidence of aromatase inhibition, though the magnitude of this effect in real-world doses is debated. The idea of using cabergoline only as a last resort is actually reasonable harm reduction, consistent with how endocrinologists approach drug-induced hyperprolactinemia.
What did they get wrong (or right)?
The P5P dose is the biggest problem here. The creator recommends "200 to 300 milligrams of P5P daily." This is not a minor error. The tolerable upper intake level for vitamin B6 set by the European Food Safety Authority is 25mg per day for adults. Chronic high-dose B6, including the active form pyridoxal-5-phosphate, has been associated with peripheral sensory neuropathy. Gdynia et al. (2008, Clinical Neuropathology) documented severe neuropathy from high-dose B6 supplementation. Doses in the 200-300mg range are used in some clinical contexts under supervision, but recommending this casually to a first-time NPP user without bloodwork or medical oversight is irresponsible.
The framing of progesterone as an "anti-androgen" is also wrong. Progesterone is a progestogen, not an anti-androgen in the pharmacological sense. It can have complex interactions with androgen signaling, but calling it an anti-androgen conflates distinct hormone categories. The creator also calls cabergoline a "dopamine antagonist" when it is actually a dopamine agonist. That is a factual error, not a slip. These are different mechanisms entirely.
What should you actually know?
If you are using nandrolone compounds, prolactin monitoring through bloodwork is the only way to know what is actually happening. Anecdotal symptom management without labs is guesswork. Gynecomastia from progestogenic and estrogenic pathways may require different interventions, and stacking multiple compounds to manage side effects of other compounds compounds risk, not reduces it.
Cabergoline is a dopamine agonist with meaningful cardiovascular implications. Zanettini et al. (2007, New England Journal of Medicine) linked cabergoline use to cardiac valvulopathy, particularly at doses used in hyperprolactinemia treatment. Using it without cardiac screening or medical oversight, even occasionally, carries real risk. The creator's admission that they personally experienced significant side effects should be taken seriously as a signal, not dismissed as routine. This is not a low-stakes optimization strategy. These are compounds with documented adverse effect profiles being combined without clinical supervision, and a TikTok comment section is not a substitute for an endocrinologist.