TRT, hormone therapy and medical weight loss in Orange County, with Dr. Castellano since 1999.
Testosterone replacement, low-T evaluation, hormone support, medical weight loss, peptide therapy, erectile dysfunction, hair loss and anti-aging medicine in Garden Grove, plus diabetes and metabolic care. Every plan starts with your labs and stays with the same board-certified physician from the first visit on.
TRT
Dr. Castellano works from the current peer-reviewed research in men's hormone medicine, not a fixed protocol. It starts with a one-hour sit-down and a focused lab panel. The dose is then set to your numbers and adjusted as your labs change. If TRT is the right call, the program is $250 a month, medication, ongoing labs and follow-up visits included. If it isn't, you'll hear that plainly, along with what to do instead.
Low testosterone evaluation
Tiredness, low drive, a flatter mood and weight around the middle are easy to put down to age. They can also come from sleep, thyroid, medications or metabolic health. The evaluation starts with a one-hour visit and a focused blood panel (total testosterone, estradiol, LH and a blood count, plus PSA when age calls for it), so the diagnosis rests on bloodwork rather than guesswork.
Hormone support
Some symptoms don't trace to testosterone alone. Hormone support reads thyroid, adrenal and metabolic markers together, ordering only the pieces your case calls for and building on bloodwork you already have. The practice is fee-for-service, so a visit runs as long as your case needs. Sometimes the answer is TRT; often it's thyroid or metabolic care instead.
Medical weight loss
Weight that stops responding to diet is often a metabolic signal: insulin resistance, a thyroid issue or a hormone change. Dr. Castellano runs a full hormone and metabolic panel before recommending anything, then builds the plan around what the labs show. Medication is used when it's the right tool, alongside nutrition and activity. No package commitments, no long-term contracts.
Peptide therapy
Peptides are a real research area, and the evidence is uneven from one to the next. Dr. Castellano reads the current literature and compounding rules alongside your labs, history and goals, and recommends a protocol only when both the evidence and the regulations support it.
Erectile dysfunction
Erectile dysfunction is often an early signal of something else: low testosterone, heart and blood-vessel health, blood sugar, sleep apnea or a medication side effect. Dr. Castellano works up the cause first, recommends a cardiology workup when warranted, and matches treatment to what the workup finds.
Hair loss
Hair loss has more than one cause, and the answer changes the treatment. Dr. Castellano checks the common drivers, including iron stores, thyroid and vitamin D, then walks through the options in order of evidence, from medication to PRP where it fits. The same physician follows your progress from the first visit on, so the plan adjusts to how your hair actually responds.
Anti-aging medicine
Board-certified in family medicine, with advanced certification in anti-aging and regenerative medicine and three decades in practice. Anti-aging here is medical, not cosmetic: labs that catch early insulin resistance, hormone decline and inflammation, then a plan built on sleep, training, nutrition, screening and, where appropriate, hormone therapy.
Metabolic and everyday conditions
Type 2 diabetes and insulin resistance
Type 2 diabetes is treated as the metabolic condition it is. Insulin resistance often shows up in the labs years before diabetes does, so Dr. Castellano tests for it directly, then builds a plan around diet, activity and medication that fits your labs, reviewing current diabetes medications step by step as your numbers change.
Fatigue
Being tired all the time is a symptom, not a diagnosis. Dr. Castellano checks the common medical drivers, including testosterone, thyroid, blood sugar, iron and vitamin levels, and treats the cause the labs point to.
Loss of muscle mass
Losing muscle despite training or eating well can point to low testosterone, metabolic change or another medical cause. Dr. Castellano finds the reason on your labs first, then treats what's driving it.
Vitamin D and B-12 deficiency
Low vitamin D and low B-12 are common and easy to miss, and both can sit behind fatigue that gets blamed on something else. Dr. Castellano checks both, corrects them when they're low, and gives B-12 injections right in the office.
Sports injuries
Strains, sprains and the aches from training that won't go away. Dr. Castellano examines the injury and puts together a plan to get you back to what you do.
Supplements in the office
Vitamins and men's health supplements, sold right in the office. Ask at your visit which ones are worth taking for you.
Also see: Anabolic Steroid Care
One conversation tells you whether this is the right fit.
Call the office to set up a 1-hour consult with Dr. Castellano. Bring whatever bloodwork you have on file — or fresh labs get ordered up front. Either way, you’ll leave with a real read on what’s going on.
Calling after hours? Leave a message — we’ll get back to you the next business day.