Kelly Osbourne undergoes a dramatic transformation at 40 after overcoming weight and addiction struggles.

On Oct. 27, Kelly Osbourne turned 40 and celebrated with her family at a party at The Bird Streets Club in West Hollywood.

The milestone birthday was fittingly celebrated with an outing, as Kelly rose to fame alongside her father, legendary rocker Ozzy Osbourne, mother Sharon, and brother Jack.

The star, who has pursued various careers in the entertainment industry, appeared significantly different from her early appearance on the family's reality show "The Osbournes," which premiered in 2002. At the time, she was just 17 years old.

Kelly wore a form-fitting floor-length gown with long sleeves and a low neckline that showcased her cleavage in photos of her arrival at the venue.

Her hair, which is blonde instead of the usual purple, was styled in an updo and secured with a black ribbon. She opted for a more neutral makeup look, featuring black eyeliner and nude lipstick.

Kelly's early days in the spotlight were marked by a more classic look, but she later adopted a more alternative style, with black, blonde or red hair and heavy makeup.

After giving birth to her son, Sidney, in 2022, she lost a considerable amount of weight and looked slimmer than ever.

""I did not take Ozempic, despite the belief that I did. My mom was the one who took it," she stated in April."

Kelly shared that she had gestational diabetes and needed to lose the weight she gained during pregnancy to reduce her risk of developing diabetes, which she did not desire. She eliminated sugar and carbohydrates from her diet and quickly shed pounds.

She underwent a non-invasive skin-tightening treatment on her stomach and neck, in addition to other areas of her body.

"After giving birth, my stomach developed numerous stretch marks, and the skin appears to have lost its elasticity," she stated.

The television personality stated in an interview with Us Weekly that she has never undergone any fillers or plastic surgery, despite having similar procedures and some Botox.

"She has always been truthful about her actions and omissions, stating that she would undergo injections all day but had never used fillers. People often commented on her overly altered appearance, to which she responded, "Actually, beneath the excess fat, I was quite attractive." Her face's shape shifted when she lost weight."

She responded, "I’m already there. I don’t want a flicky neck, so I’ll get that cleaned up. I don’t want jowls, which I feel like I’m starting to get. There’s a way to do it gracefully. I don’t wanna change my face. I want to get my t--s done. They look droopy and saggy, but I’m too scared. I’m already in pain, and what if it goes wrong?"

She stated that she is not currently focused on her weight and does not exercise.

Since undergoing gastric bypass surgery in 2020, the star has lost 85 pounds.

In a 2022 episode of the "Hollywood Raw" podcast, she stated, "I underwent surgery; I don't care what others think. I did it, and I'm proud of it. . . . I had a gastric sleeve. It only alters the shape of your stomach. I got it nearly two years ago. I will never lie about it, ever. It is the greatest thing I have accomplished."

Kelly mentioned that she would undergo "stand-alone therapy" for a year prior to the surgery, stating that the operation "eliminates the hormone that, if you have addiction problems, reduces your cravings and prevents emotional eating, which is a significant issue for me."

She stated that it is merely a step in the right direction, not a comprehensive solution to all problems, and not a quick fix.

She has openly discussed her struggles with both weight and addiction. In a podcast interview, she stated that in order to achieve a healthy body, she first needed to address her mind and become sober.

In a 2021 episode of Red Table Talk, Kelly revealed that her addiction started when she was 13. Following a severe tonsillitis, she underwent surgery and was prescribed Vicodin during her recovery.

"Taking the painkiller was all I needed," she recalled. "I went from feeling like every voice in my head was telling me I was fat, ugly, not good enough, unliked, and undeserving to having all the voices suddenly quiet, and it felt like life gave me a hug."

Kelly admitted that after taking Vicodin, she started taking Percocet and eventually turned to heroin because it was more affordable.

In an episode of "TMZ Investigates: Matthew Perry & The Secret Celebrity Drug Ring" last month, she revealed that going to rehab at 19 was like attending university on how to become a better drug addict.

She shared that she had learned numerous tricks and techniques from her fellow addicts that she had never considered before. Additionally, she had witnessed individuals threaten to depart until they received what they desired, whether it was Ambien for sleep or Valium for anxiety - ultimately, they would obtain it.

Over the years, she visited various rehab centers seven times before achieving sobriety in 2017. In 2021, she briefly relapsed but kept it a secret until she was back on track.

She shared on social media that she is sober today and will be tomorrow, but she has learned that it's just one day at a time.

She admitted to Extra that she had a "nervous breakdown" which led to her temporary lapse, stating, "I'm that girl who, when everything is going great, needs to mess things up a little and make them worse in my life. I'm an addict who thought I had enough time under my belt and could drink like a normal person, but it turned out I couldn't, and I'll never be normal. I don't know why I even tried it. It's not for me, and it took me just a few days to realize it."

She is now feeling grateful for everything that has led her to her current position.

"She expressed her gratitude for every mistake she made, every lesson learned, and all of it. She stated that turning 40 is an opportunity to embrace her true self and let go of the past. She can start anew and leave behind the shame of being an addict."