Rachel Deutsch, DNP, built Tides for a reason. She came out of emergency medicine, neurology, regenerative care, and aesthetics. For a lot of her patients, diet and exercise had already done what they can. The biology underneath had not. She made it telemedicine on purpose. People should be able to learn why a compound belongs, then actually get it, with a clinician on the case. CoQ10 next to a statin. Methylcobalamin when B12 is the leak. Not a quiz that auto ships a vial. She still reads every intake herself. If it does not fit, it does not ship. That is the whole product.

It's good to see more men getting access to care for low testosterone. One thing worth knowing before you start: testosterone from outside tells the pituitary to turn down LH and FSH, the testes depend on that signal to make sperm, and counts fall in most men. Most men recover after stopping, but it can take months and sometimes more than a year, so the order of decisions matters if you might want kids. A semen analysis before starting gives you a baseline, and it's a simple question to raise at your first visit. If you're on TRT now, did anyone ask you about fertility before you started?

If you have ever heard enclomiphene described as "testosterone in a pill," it is worth clearing up, because the difference changes who it makes sense for. A common myth is that enclomiphene is a form of testosterone. The fact is that it contains no testosterone at all. It works one step upstream, at the pituitary. By easing estrogen's brake there, it lets LH and FSH rise, and those are the signals that tell the testes to make their own testosterone and sperm. That is why it is only a fit when the testes can still answer the signal, and why a clinician looks at LH and FSH, not just the testosterone number. So if you are reading about it, the takeaway is simple. Ask whether the plan replaces your testosterone or helps your body make its own, because those are two different paths. Enclomiphene is prescribed as a compounded medication, and compounded medications are not FDA-approved.

If you have ever wondered why the same cream gets prescribed for teenage acne and for sun-damaged skin at 50, it comes down to one molecule doing two jobs. Tretinoin works on the lining of the pore, helping the skin shed cells normally so they stop clumping into the plugs that start a breakout. Deeper down, it acts on the cells that build collagen, and over months that is what softens fine lines and evens out rough texture. That is also why people using it for acne often notice their skin looks smoother overall, and why people using it for aging sometimes see fewer clogged pores along the way. The takeaway is patience. The pore changes can show up in weeks, while the collagen changes take months, so judging it at week four sells it short.

Thinning hair? Prescription hair-loss treatments are available today. A licensed Tides clinician can review your history in one online visit and tell you whether one may fit you. Compounded medications are not FDA-approved. Start here: gettides.com/intake.html?goa…

A single low testosterone result is a reason to test again rather than a diagnosis. Testosterone peaks in the early morning and moves from day to day, so both the American Urological Association and the Endocrine Society ask for two separate early-morning measurements before calling it low. The more useful workup adds LH and FSH, which show whether the pituitary or the testes are the source of the problem, along with SHBG, since an unusually high or low binding protein can make total testosterone misleading, and estradiol, which matters for symptoms and for monitoring once treatment starts. Prolactin is added when LH is low or normal despite low testosterone, because a pituitary cause has to be ruled out before the number itself is treated.

Tirzepatide slows how quickly the stomach empties, and that matters for other medicines taken by mouth as well as for appetite. The clearest example is the birth control pill, because a pharmacology study found that tirzepatide lowered blood levels of a combined oral contraceptive, which is why the prescribing information advises switching to a non-oral method, or adding a barrier method, for four weeks after starting and after each dose increase. The same slowing is why a clinician reviewing a tirzepatide plan, oral or injected, asks about every other medication, particularly ones like warfarin where small changes in absorption can matter.

Most of semaglutide's effect on weight lasts only as long as it is taken, and the STEP 1 extension showed what happens after it stops. Adults who had lost about 17 percent of their body weight on average over 68 weeks stopped both the medicine and the structured lifestyle program, and a year later they had regained about two-thirds of that loss, with blood pressure, blood sugar, and other improvements drifting back toward where they started. That result supports treating obesity as a chronic condition, where the plan for maintenance matters as much as the plan for getting started. Compounded medications are not FDA-approved. If you'd like a clinician to review whether semaglutide fits your history and labs, you can start at gettides.com/intake.html?goa…

CoQ10 is generally well tolerated, but people who take warfarin should know about one interaction. CoQ10 is structurally similar to vitamin K, and case reports have described the INR falling after people on warfarin started taking it, although a small randomized trial found no meaningful change in INR. Because warfarin has such a narrow margin between too little and too much effect, the sensible approach is to tell the prescribing clinician and recheck the INR after starting or stopping CoQ10, the same way any new supplement would be handled.

Testosterone therapy and fertility pull in opposite directions for a reason that surprises a lot of men. Sperm production depends on testosterone made inside the testes, where levels run many times higher than in the blood, and that local supply is driven by LH from the pituitary. When testosterone is given from outside, the pituitary reads the higher blood level as a signal to turn LH and FSH down, so the testes make less of their own testosterone and less sperm, even while the blood number looks excellent. Enclomiphene works on the same feedback loop from the other side, easing estrogen's brake at the pituitary so that LH and FSH rise and the testes can keep making both.

The most common reason people give up on topical minoxidil early is a shed in the first couple of months, and it is usually a sign that the follicles are responding. Minoxidil pushes resting follicles into a new growth phase, so the old hairs they were holding are released first, typically starting a few weeks in and settling over the following weeks as new growth comes through. The same process runs in reverse when treatment stops, since the hairs it was supporting tend to shed within a few months, which is why it helps to think of minoxidil as a long-term treatment from the start.

Tirzepatide's effect on weight has had a practical consequence for sleep medicine. In the SURMOUNT-OSA trials in adults with obesity and moderate to severe obstructive sleep apnea, breathing interruptions during sleep fell by about half or more on tirzepatide, compared with small changes on placebo, and in late 2024 it became the first medicine FDA-approved for that condition in people with obesity. It does not replace a sleep study or CPAP for everyone, but for many patients it means weight treatment and sleep apnea treatment can be planned together rather than separately. If you'd like a clinician to look at whether tirzepatide fits your history and labs, you can start at gettides.com/intake.html?goa…

Cells build glutathione from three amino acids, glutamate, cysteine, and glycine, and the supply of cysteine is usually the step that limits how fast it can be made. That is why N-acetylcysteine, which delivers cysteine, has long been used in hospitals to restore glutathione, and why small trials in older adults have tested cysteine and glycine together and reported higher glutathione levels and lower markers of oxidative stress. Those trials have been small and short, so the fair reading is that the building blocks can raise glutathione in people who run low, while effects on longer-term health outcomes have not been established.

Most discussion of NAD+ and aging focuses on making more of it, but some of the decline may come from faster use rather than slower production. Enzymes such as CD38, which sits on immune cells and rises with inflammation, break NAD+ down, and in mouse studies CD38 activity increased with age in a way that tracked the fall in tissue NAD+. That work is still mostly in animals, but it is one reason researchers think chronic inflammation, physical activity, and sleep may matter as much as any precursor when it comes to keeping levels up.

Tretinoin and over-the-counter retinol are often described as stronger and weaker versions of the same thing, but the difference is more specific than that. Retinol has to be converted by enzymes in the skin, first into retinaldehyde and then into retinoic acid, before it can act on the receptors that drive the collagen and cell-turnover changes, and only part of it makes it through those steps. Tretinoin is retinoic acid itself, which is why it tends to work faster and irritate more, and why it carries the long record of randomized photoaging trials that retinol largely lacks.

Tadalafil is FDA-approved not only for erectile dysfunction but also for the urinary symptoms of an enlarged prostate, such as a weak stream and getting up at night to urinate. The enzyme it blocks, PDE5, is also present in the smooth muscle of the prostate and bladder neck, so relaxing that tissue can ease urinary flow in addition to improving blood flow during arousal. For men who have both problems, one medicine can address both, although nitrates and some blood pressure medicines need to be reviewed first because the combination can lower blood pressure too far. If you'd like a clinician to look at your history and whether tadalafil fits, you can start at gettides.com/intake.html?goa…

Clomiphene, a fertility drug that has been used off-label in men for decades, is actually a mixture of two geometric isomers. Enclomiphene, the trans isomer, is the one that blocks estrogen feedback at the pituitary and raises LH and FSH, while zuclomiphene, the cis isomer, clears slowly, can remain detectable for weeks, and has weak estrogen-like effects of its own. Isolating enclomiphene was meant to keep the useful action without that slow buildup, although direct comparisons in men are still limited, so a clinician follows testosterone, LH, and FSH to confirm it is working.

Most discussion of GHK-Cu focuses on the peptide, but the copper it carries does much of the work. The peptide binds copper tightly enough to deliver it to skin cells in a gentle, usable form, and copper is required by lysyl oxidase, the enzyme that cross-links collagen and elastin so that new fibers become strong and organized. That pairing is a large part of the rationale for the copper-bound form, and it is also why the reasonable expectation, based on small human studies, is gradual improvement in skin quality over months of topical use rather than dramatic or whole-body effects.