Skip to content
Castellano Health Institute
Men's Health Physician · Garden Grove

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. Every plan starts with your labs and stays with the same board-certified physician from the first visit on.

Rated 5.0 on Google across 35 patient reviews

A man in his forties jogging a coastal path at sunrise, smiling, with a pier behind him
01

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.

More about TRT→

A man in his forties pouring coffee in a sunlit kitchen after a morning workout, laughing
02

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.

More about low testosterone→

A man in his forties with a daypack pausing on a hillside trail, looking out over the valley
03

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.

More about hormone support→

A couple in their forties cooking a vegetable-heavy dinner together in their kitchen, laughing
04

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.

More about medical weight loss→

A man in his forties resting on a weight bench in a garage gym, towel over his shoulder
05

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.

More about peptide therapy→

A couple in their forties embracing on the beach at golden hour, laughing with each other
06

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.

More about erectile dysfunction→

A man checking his hairline in the mirror
07

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. The same physician follows your progress from the first visit on, so the plan adjusts to how your hair actually responds.

More about hair loss→

A man in his forties mid-swing on a pickleball court, eyes on the ball
08

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.

More about anti-aging medicine→

Ready when you are

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.